Descriptive statistics and descriptive analysis are statistical methods used to analyze and summarize data. Descriptive statistics focus on summarizing central tendency and variability measures, while descriptive analysis involves observing, collecting, organizing, and summarizing data to identify patterns and relationships between variables. Both methods are valuable in understanding and interpreting data. Examples of descriptive statistics include analyzing class scores, heights, household income, and traffic numbers. Both methods help in understanding and interpreting data effectively.
Descriptive Statistics:
Descriptive Statistics, also known as summary statistics, is a statistical method used to organize, describe, and sum up data in a meaningful way. It helps to highlight the main features of the data set. Descriptive statistics deal with quantitative and qualitative data and involve measures of central tendency (mean, median, mode) and measures of variability (range, variance, standard deviation).
Example of Descriptive Statistics:
The mean of the class score was 85%.
The mode of the data was 20.
The range of the heights of the students was 120-180 cm.
The median household income was $70,000.
The standard deviation of the number of cars on the road is 2.5.
Descriptive Analysis:
Descriptive Analysis is a research method that involves observing, collecting, organizing, and summarizing data to describe a set of variables or phenomena. It utilizes various methods such as graphs, tables, and charts to provide a clear understanding of the data. Descriptive analysis helps to identify patterns and relationships between variables.
Example of Descriptive Analysis:
Analyzing the patterns of consumer spending on a particular product.
Describing the proportion of a population that is over 65 years of age.
Analyzing the characteristics of the members of a particular community.
Describing the frequency of occurrence of certain diseases in a population.
Analyzing the distribution of crime in a city.
Conclusion:
Descriptive statistics and descriptive analysis are statistical methods used to analyze and summarize data. Descriptive statistics focus on summarizing the basic features of data, such as measures of central tendency and variability. Descriptive analysis, on the other hand, involves observing and summarizing data to gain an overview, identify patterns, and find relationships between variables. Both methods are valuable in understanding and interpreting data.
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Which of the following is the appropriate substitution for the Bernoulli differential equation xyy ′−2xy=4xy 2? Letz= y ∧−1 y ∧−3 y ∧ −4 (D) y∧ −2
To solve the Bernoulli differential equation xyy' - 2xy = 4xy^2, we can make the substitution z = y^(1-2) = y^(-1). The appropriate substitution is z = y^(-2), not one of the options listed. This substitution simplifies the equation and transforms it into a separable first-order differential equation. By Differentiating both sides of the equation with respect to x, we get: dz/dx = d(y^(-1))/dx
Using the chain rule, we have:
dz/dx = (-1)(y^(-2))(dy/dx)
dz/dx = -y^(-2)dy/dx
Substituting this into the original differential equation, we have:
xy(-y^(-2)dy/dx) - 2xy = 4xy^2
Simplifying, we get:
-y(dy/dx) - 2 = 4y^2
Now, we have a separable first-order differential equation. By rearranging terms, we get:
dy/dx = -(4y^2 + 2)/y
To further simplify the equation, we can substitute z = y^(-2), giving us:
dy/dx = -(-4z + 2)
Therefore, the appropriate substitution for the Bernoulli differential equation is z = y^(-2), not one of the options listed.
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[3] Convert (BEC.17D) 16 into Octal. Hint: See example 1.20 in Text Book [4] (i) What is two's complement number system ? (ii) Why is it used ? (iii) What are the twomethods to convert a number
Convert (BEC.17D)16 to octal using methods: 1. Hex to binary to octal. 2. Hex to decimal to octal.
To convert (BEC.17D)₁₆ to octal, we divide the hexadecimal number into two parts: the integer part and the fractional part.
(i) The two's complement number system is a method of representing signed numbers in binary. It involves flipping the bits and adding 1 to the least significant bit to obtain the negative representation of a number.
(ii) Two's complement is used because it simplifies arithmetic operations on signed numbers, allowing addition and subtraction to be performed using the same logic.
(iii) There are two methods to convert a number from hexadecimal to octal:
Convert the hexadecimal number to binary and then convert the binary number to octal.
Convert the hexadecimal number to decimal and then convert the decimal number to octal.
For the given hexadecimal number (BEC.17D)₁₆, we can use either method to convert it to octal.
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A manufacturer of boiler drums wants to use regression to predict the number of hours needed to erect drums in the future. The manufacturer collected a random sample of 35 boilers and measured the following two variables:
LABHRS: y = Number of labour-hours required to erect the drum
Marked out of
PRESSURE: x= Boiler design pressure (pounds per square inch, i.e., psi)
The results of the linear regression analysis yielded the equation:
LABHRS = 1.88 +0.32 PRESSURE
Give a practical interpretation of the estimate of the y-intercept of the line.
Hint: When interpreting the "y-intercept" give consideration to whether it is a meaningful interpretation in context.
Select one:
A.We estimate the number of labour hours to increase 0.32 when the deigned pressure increases by 1 pound per square inch.
B.We estimate the number of labour hours to increase 1.88 when the deigned pressure increases by 1 pound per square inch.
C.All boiler drums in the sample had a design pressure of at least 1.88 pounds per square inch.
D.We expect it to take at least 0.32 man hours to erect a boiler drum.
E. We expect it to take at least 1.88 man hours to erect a boiler drum.
Option B is the correct answer.
LABHRS = 1.88 + 0.32 PRESSURE The given regression model is a line equation with slope and y-intercept.
The y-intercept is the point where the line crosses the y-axis, which means that when the value of x (design pressure) is zero, the predicted value of y (number of labor hours required) will be the y-intercept. Practical interpretation of y-intercept of the line (1.88): The y-intercept of 1.88 represents the expected value of LABHRS when the value of PRESSURE is 0. However, since a boiler's pressure cannot be zero, the y-intercept doesn't make practical sense in the context of the data. Therefore, we cannot use the interpretation of the y-intercept in this context as it has no meaningful interpretation.
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5. Equivalence ( 4 points) Prove that the following are equivalent for all a, b \in{R} : (i) a is less than b , (ii) the average of a and b is greater than a
The following are equivalent for all a,b , (i) implies (ii) and (ii) implies (i), we can conclude that the statements (i) and (ii) are equivalent for all real numbers a and b.
To prove the equivalence of the statements (i) and (ii) for all real numbers a and b, we need to show that (i) implies (ii) and (ii) implies (i).
(i) a < b implies (ii) the average of a and b is greater than a:
Assume a < b. We want to show that the average of a and b is greater than a, i.e., (a + b) / 2 > a.
Multiplying both sides of the inequality a < b by 2, we have 2a < 2b.
Adding a to both sides, we get 2a + a < 2b + a, which simplifies to 3a < a + b.
Dividing both sides by 3, we have (3a) / 3 < (a + b) / 3, resulting in a < (a + b) / 2.
Therefore, (i) implies (ii).
(ii) the average of a and b is greater than a implies (i) a < b:
Assume (a + b) / 2 > a. We want to show that a < b.
Multiplying both sides of the inequality by 2, we have a + b > 2a.
Subtracting a from both sides, we get b > a.
Therefore, (ii) implies (i).
Since we have shown that (i) implies (ii) and (ii) implies (i), we can conclude that the statements (i) and (ii) are equivalent for all real numbers a and b.
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For each of the following subsets of a given vector space, determine if the subset
W
is a subspace of
V
. a)
W={(x 1
,x 2
,x 3
,x 4
)εR 4
∣x 1
+2x 3
−3x 4
=0}V=R 4
b)
W={BεA 3×3
∣∣B∣=0}V=A 3×3
c)
W={p(x)εP 3
∣p(x)=a 3
x 3
+a 2
x 2
+a 1
x}V=P 3
d)
W={BεA 2×2
∣B=[ a
0
b
d
]}V=A 2×2
The sets of vectors that are subspaces of R3 are:
1. all x such that x₂ is rational
2. all x such that x₁ + 3x₂ = x₃
3. all x such that x₁ ≥ 0
Set of vectors where x₂ is rational: To determine if this set is a subspace, we need to check if it satisfies the two conditions for a subspace: closure under addition and closure under scalar multiplication.
Set of vectors where x₂ = x₁²: Again, we need to verify if this set satisfies the two conditions for a subspace.
Closure under addition: Consider two vectors, x = (x₁, x₂, x₃) and y = (y1, y2, y3), where x₂ = x₁² and y2 = y1².
If we add these vectors, we get
z = x + y = (x₁ + y1, x₂ + y2, x₃ + y3).
For z to be in the set, we need
z2 = (x₁ + y1)².
However, (x₁ + y1)² is not necessarily equal to
x₁² + y1², unless y1 = 0.
Therefore, the set is not closed under addition.
Closure under scalar multiplication: Let's take a vector x = (x₁, x₂, x₃) where x₂ = x₁² and multiply it by a scalar c. The resulting vector cx = (cx₁, cx₂, cx₃) has cx₂ = (cx₁)². Since squaring a scalar preserves its non-negativity, cx₂ is non-negative if x₂ is non-negative. However, this set allows for negative values of x₂ (e.g., (-1, 1, 0)), which means cx₂ can be negative as well. Therefore, this set is not closed under scalar multiplication.
Conclusion: The set of vectors where x₂ = x₁² is not a subspace of R3.
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Complete Question:
Which of the following set of vectors x = (x₁, x₂, x₃) and R³ is a subspace of R³?
1. all x such that x₂ is rational
2. all x such that x₁ + 3x₂ = x₃
3. all x such that x₁ ≥ 0
4. all x such that x₂=x₁²
A newspaper regularly reports the air quality index for various areas of Southern California. A sample of air quality index values for Pomona provided the following data: 28,43,58,49,46,56,60,50, and 51. (a) Compute the range and interquartile range. range interquartile range (b) Compute the sample variance and sample standard deviation. (Round your answers to two decimal places.) sample variance sample standard deviation (c) A sample of air quality index readings for Anaheim provided a sample mean of 48.5, a sample variance of 136, and a sample standard deviation of 11.66. What comparisons can you make between the air quality in Pomona and that in Anaheim on the basis of these descriptive statistics? The average air quality in Anaheim is the average air quality in Pomona. The variability is greater in
Range = 32, Interquartile range = 12.
Given data, Pomona = {28, 43, 58, 49, 46, 56, 60, 50, 51}
(a) Range: The range of the air quality index values for Pomona can be calculated by subtracting the minimum value from the maximum value. Here, the minimum value is 28, and the maximum value is 60.
Range = Maximum value - Minimum value
= 60 - 28= 32
Interquartile Range: The difference between the third quartile (Q3) and the first quartile (Q1) is called the interquartile range (IQR). The IQR measures the variability in the middle 50% of the data.
IQR = Q3 - Q1
= 56 - 44
= 12
(b) Sample Variance and Sample Standard Deviation: Sample Variance:It is the measure of the spread of the data in a sample about its mean. The formula to calculate the sample variance is:Sample Variance,
s² = [∑(x - μ)² / (n - 1)]
Where, ∑ = Summation symbolx = Value of the observation μ = Mean of the observations n = Total number of observations Substitute the given values in the above formula, we get
Sample variance, s² = [∑(x - μ)² / (n - 1)]
= [∑(x - 48.5)² / (n - 1)]
= [∑(x² - 97x + 2352.25) / 8]
= (9664 - 7765) / 8
= 189.88 (Approx)
Therefore, sample variance, s² = 189.88
Sample Standard Deviation:It is a measure of the spread of the data in a sample about its mean. It can be calculated by taking the square root of the sample variance.Sample Standard Deviation, s = √s²Substitute the calculated sample variance in the above formula, we get Sample Standard Deviation,
s = √189.88≈ 13.78
Therefore, sample standard deviation, s = 13.78
The given sample of air quality index values for Anaheim provides a sample mean of 48.5, a sample variance of 136, and a sample standard deviation of 11.66. From the calculated measures of central tendency and measures of dispersion, it can be concluded that the average air quality in Anaheim is similar to the average air quality in Pomona.However, the variability is greater in Anaheim as the sample variance and sample standard deviation of Anaheim are more than the sample variance and sample standard deviation of Pomona.
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Let
Yj = 0 if j Is pair
Yj = Xj if j Is odd
determinate the eigenvalues of T and it's eigenspaces
T: K[infinity] ⟶ K[infinity]
x ⟶ y,
yj ={ 0 si j es par, xj si j es impar.
The eigenvalues of T are λ = 0 and λ ≠ 0, and the corresponding eigenspaces are E0 and Eλ, respectively. We need to find the values of λ for which T(x) = λx has a nontrivial solution.
Let's consider an arbitrary element x = (x1, x2, x3, ...) in K[infinity]. Applying T to x, we get:
T(x) = (y1, y2, y3, ...) = (0, λx2, 0, λx4, 0, λx6, ...)
We can observe that each coordinate of T(x) is determined by the corresponding coordinate of x, and the even coordinates become zero. Therefore, the eigenvalues of T are λ = 0 and λ ≠ 0, with corresponding eigenspaces E0 and Eλ, respectively.
For the eigenvalue λ = 0, the eigenspace E0 consists of all vectors x = (x1, x2, x3, ...) such that yj = 0 for all j. In other words, E0 is the set of all sequences x in K[infinity] with even-indexed entries being arbitrary and odd-indexed entries being zero.
For the eigenvalue λ ≠ 0, the eigenspace Eλ consists of all vectors x = (x1, x2, x3, ...) such that yj = λxj for all j. In this case, every entry in the sequence x contributes to the corresponding entry in the sequence y with the scaling factor of λ. Therefore, Eλ is the set of all sequences x in K[infinity] with both even-indexed and odd-indexed entries being arbitrary.
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For each f(n) below find the simplest and most accurate functions g 1
(n),g 2
(n) and g 3
(n) such that f(n)=O(g 1
(n)) and f(n)=Ω(g 2
(n)) and f(n)=Θ(g 3
(n)). a) f(n)=∑ i=1
n 3
i 2
b) f(n)=log( n 2
+n+log(n)
n 4
+2n 3
+1
) c) f(n)=∑ i=1
n
(i 3
+2i 2
) d) f(n)=∑ i=1
n
log(i 2
) e) f(n)=∑ i=1
log(n)
i
f(n) always lies between n³ and (n+1)³ so we can say that f(n) = Θ(n³). As f(n) lies between n⁻² and n⁻⁴log n, we can say that f(n) = Θ(n⁻²). As f(n) lies between n³ and 3n⁴/4 + n³, we can say that f(n) = Θ(n⁴). As f(n) lies between nlogn and 2nlogn, we can say that f(n) = Θ(nlogn). As f(n) lies between log(n) and log(n)², we can say that f(n) = Θ(log(n)²).
(a) f(n) = Θ(n³) Here we need to find the simplest and most accurate functions g1(n), g2(n), and g3(n) for each f(n). The given function is f(n) = Σi=1n 3i². So, to find g1(n), we will take the maximum possible value of f(n) and g1(n). As f(n) will always be greater than n³ (as it is the sum of squares of numbers starting from 1 to n). Therefore, g1(n) = n³. Hence f(n) = O(n³).Now to find g2(n), we take the minimum possible value of f(n) and g2(n). As f(n) will always be less than (n+1)³. Therefore, g2(n) = (n+1)³. Hence f(n) = Ω((n+1)³). Now, to find g3(n), we find a number c1 and c2, such that f(n) lies between c1(n³) and c2((n+1)³) for all n > n₀ where n₀ is a natural number. As f(n) always lies between n³ and (n+1)³, we can say that f(n) = Θ(n³).
(b) f(n) = Θ(log n) We are given f(n) = log((n² + n + log n)/(n⁴ + 2n³ + 1)). Now, to find g1(n), we will take the maximum possible value of f(n) and g1(n). Let's observe the terms of the given function. As n gets very large, log n will be less significant than the other two terms in the numerator. So, we can assume that (n² + n + log n)/(n⁴ + 2n³ + 1) will be less than or equal to (n² + n)/n⁴. So, f(n) ≤ (n² + n)/n⁴. So, g1(n) = n⁻². Hence, f(n) = O(n⁻²).Now, to find g2(n), we will take the minimum possible value of f(n) and g2(n). To do that, we can assume that the log term is the only significant term in the numerator. So, (n² + n + log n)/(n⁴ + 2n³ + 1) will be greater than or equal to log n/n⁴. So, f(n) ≥ log n/n⁴. So, g2(n) = n⁻⁴log n. Hence, f(n) = Ω(n⁻⁴log n).Therefore, g3(n) should be calculated in such a way that f(n) lies between c1(n⁻²) and c2(n⁻⁴log n) for all n > n₀. As f(n) lies between n⁻² and n⁻⁴log n, we can say that f(n) = Θ(n⁻²).
(c) f(n) = Θ(n³)We are given f(n) = Σi=1n (i³ + 2i²). So, to find g1(n), we take the maximum possible value of f(n) and g1(n). i.e., f(n) will always be less than or equal to Σi=1n i³ + Σi=1n 2i³. Σi=1n i³ is a sum of cubes and has a formula n⁴/4 + n³/2 + n²/4. So, Σi=1n i³ ≤ n⁴/4 + n³/2 + n²/4. So, f(n) ≤ 3n⁴/4 + n³. So, g1(n) = n⁴. Hence, f(n) = O(n⁴).Now, to find g2(n), we take the minimum possible value of f(n) and g2(n). i.e., f(n) will always be greater than or equal to Σi=1n i³. So, g2(n) = n³. Hence, f(n) = Ω(n³).To find g3(n), we should find a number c1 and c2 such that f(n) lies between c1(n⁴) and c2(n³) for all n > n₀. As f(n) lies between n³ and 3n⁴/4 + n³, we can say that f(n) = Θ(n⁴).
(d) f(n) = Θ(n log n)We are given f(n) = Σi=1n log(i²). So, to find g1(n), we take the maximum possible value of f(n) and g1(n). i.e., f(n) will always be less than or equal to log(1²) + log(2²) + log(3²) + .... + log(n²). Now, the sum of logs can be written as a log of the product of terms. So, the expression becomes log[(1*2*3*....*n)²]. This is equal to 2log(n!). As we know that n! is less than nⁿ, we can say that log(n!) is less than nlog n. So, f(n) ≤ 2nlogn. Therefore, g1(n) = nlogn. Hence, f(n) = O(nlogn).To find g2(n), we take the minimum possible value of f(n) and g2(n). i.e., f(n) will always be greater than or equal to log(1²). So, g2(n) = log(1²) = 0. Hence, f(n) = Ω(1).To find g3(n), we should find a number c1 and c2 such that f(n) lies between c1(nlogn) and c2(1) for all n > n₀. As f(n) lies between nlogn and 2nlogn, we can say that f(n) = Θ(nlogn).
(e) f(n) = Θ(log n)We are given f(n) = Σi=1logn i. So, to find g1(n), we take the maximum possible value of f(n) and g1(n). i.e., f(n) will always be less than or equal to logn + logn + logn + ..... (log n terms). So, f(n) ≤ log(n)². Therefore, g1(n) = log(n)². Hence, f(n) = O(log(n)²).To find g2(n), we take the minimum possible value of f(n) and g2(n). i.e., f(n) will always be greater than or equal to log 1. So, g2(n) = log(1) = 0. Hence, f(n) = Ω(1).To find g3(n), we should find a number c1 and c2 such that f(n) lies between c1(log(n)²) and c2(1) for all n > n₀. As f(n) lies between log(n) and log(n)², we can say that f(n) = Θ(log(n)²).
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consider the following list of numbers. 127, 686, 122, 514, 608, 51, 45 place the numbers, in the order given, into a binary search tree.
The binary search tree is constructed using the given list of numbers: 127, 122, 51, 45, 686, 514, 608.
To construct a binary search tree (BST) using the given list of numbers, we start with an empty tree and insert the numbers one by one according to the rules of a BST.
Here is the step-by-step process to construct the BST:
1. Start with an empty binary search tree.
2. Insert the first number, 127, as the root of the tree.
3. Insert the second number, 686. Since 686 is greater than 127, it becomes the right child of the root.
4. Insert the third number, 122. Since 122 is less than 127, it becomes the left child of the root.
5. Insert the fourth number, 514. Since 514 is greater than 127 and less than 686, it becomes the right child of 122.
6. Insert the fifth number, 608. Since 608 is greater than 127 and less than 686, it becomes the right child of 514.
7. Insert the sixth number, 51. Since 51 is less than 127 and less than 122, it becomes the left child of 122.
8. Insert the seventh number, 45. Since 45 is less than 127 and less than 122, it becomes the left child of 51.
The resulting binary search tree would look like this.
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A shoe store advertised a sale for 35% off all sneakers. If the list price of a pair of sneakers was $80, what was (a) the discount and (b) the sale price of the sneakers?
If a shoe store advertised a sale for 35% off all sneakers and the list price of a pair of sneakers was $80, then the discount is $28 and the sale price of the sneakers is $52.
(a) To find the discount, follow these steps:
The discount amount can be calculated by using the following formula: Discount = List price × Discount rateSo, :Discount = $80 × 35% = 80 ×0.35= $28.Therefore, the discount is $28.
(b) To find the sale price of the sneakers, follow these steps:
The sale price can be calculated by subtracting the discount amount from the list price. So, the formula to find the sale price is Sale price = List price − DiscountSubstituting the values, we get the sale price = $80 − $28 = $52.Thus, the sale price of the sneakers after the discount is $52.
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5. In any metric space (M,D), prove that D(a 1 ,an )≤D(a1 ,a 2 )+ D(a ,a 3 )+⋯+D(a n−1 ,a n ), for a 1 ,a ,…,an ∈M. 1
D(a₁, an) ≤ D(a₁, a₂) + D(a₂, a₃) + ⋯ + D(aₙ₋₁, aₙ) for any metric space (M, D) and elements a₁, a₂, ..., aₙ ∈ M.
To prove the inequality D(a₁, an) ≤ D(a₁, a₂) + D(a₂, a₃) + ⋯ + D(aₙ₋₁, aₙ) for any metric space (M, D) and elements a₁, a₂, ..., aₙ ∈ M, we can use the triangle inequality property of a metric space.
The triangle inequality states that for any three points x, y, and z in a metric space, the distance between x and z is always less than or equal to the sum of the distances between x and y, and between y and z. Mathematically, it can be written as:
D(x, z) ≤ D(x, y) + D(y, z)
Now, let's consider the elements a₁, a₂, ..., aₙ ∈ M.
By applying the triangle inequality repeatedly, we can write:
D(a₁, aₙ) ≤ D(a₁, a₂) + D(a₂, a₃) + ... + D(aₙ₋₁, aₙ)
This inequality holds because we can view the distance between a₁ and aₙ as the sum of the distances between adjacent points in the sequence a₁, a₂, ..., aₙ.
Therefore, we have proved that D(a₁, an) ≤ D(a₁, a₂) + D(a₂, a₃) + ⋯ + D(aₙ₋₁, aₙ) for any metric space (M, D) and elements a₁, a₂, ..., aₙ ∈ M.
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start fraction, 2, divided by, 7, end fraction of a meter of ribbon to make bows for her cousins. Now, she has \dfrac{10}{21}
21
10
start fraction, 10, divided by, 21, end fraction of a meter of ribbon left.
How much ribbon did Jennifer start with?
Jennifer started with 2/3 of a meter of ribbon. By subtracting the amount she has left (10/21) from the amount she used to make the bows (2/7), we find that she used 4/21 more than she had initially. Adding this difference to the remaining ribbon gives a final answer of 2/3.
To find out how much ribbon Jennifer started with, we can subtract the amount she has left from the amount she used to make the bows. Jennifer used 2/7 of a meter of ribbon, and she has 10/21 of a meter left.
To make the subtraction easier, let's find a common denominator for both fractions. The least common multiple of 7 and 21 is 21. So we'll convert both fractions to have a denominator of 21.
2/7 * 3/3 = 6/21
10/21
Now we can subtract:
6/21 - 10/21 = -4/21
The result is -4/21, which means Jennifer used 4/21 more ribbon than she had in the first place. To find the initial amount of ribbon, we can add this difference to the amount she has left:
10/21 + 4/21 = 14/21
The final answer is 14/21 of a meter. However, we can simplify this fraction further. Both the numerator and denominator are divisible by 7, so we can divide them both by 7:
14/21 = 2/3
Therefore, Jennifer started with 2/3 of a meter of ribbon.
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The probable question may be:
Jennifer used 2/7 of a meter of ribbon to make bows for her cousins. Now, she has 10/21 of a meter of ribbon left. How much ribbon did Jennifer start with?
points A B and C are collinear point Bis between A and C find BC if AC=13 and AB=10
Collinearity has colorful activities in almost the same important areas as math and computers.
To find BC on the line AC, subtract AC from AB. And so, BC = AC - AB = 13 - 10 = 3. Given collinear points are A, B, C.
We reduce the length AB by the length AC to get BC because B lies between two points A and C.
In a line like AC, the points A, B, C lie on the same line, that is AC.
So, since AC = 13 units, AB = 10 units. So to find BC, BC = AC- AB = 13 - 10 = 3. Hence we see BC = 3 units and hence the distance between two points B and C is 3 units.
In the figure, when two or more points are collinear, it is called collinear.
Alignment points are removed so that they lie on the same line, with no curves or wandering.
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You have a triangle. An angle is 120 ∘
. An adjacent side measures 2 cm and the opposite side V19 cm. Determine the third side. Count by hand, and accurately! (b) Draw your triangle to scale using a ruler and protractor, and check that the calculated value is correct. (Hore you can use a calculator to get the measurements as a decimal expression.)
The length of the third side of the triangle is approximately 5.457 cm. To verify our result, by measuring the sides of the triangle accurately, we can confirm if the calculated value of approximately 5.457 cm is correct.
To determine the length of the third side of the triangle, we can use the law of cosines, which relates the lengths of the sides of a triangle to the cosine of one of its angles. The law of cosines states:
c^2 = a^2 + b^2 - 2ab*cos(C)
where c is the length of the side opposite angle C, and a and b are the lengths of the other two sides.
In this case, we are given that angle C is 120 degrees, side a has a length of 2 cm, and side b has a length of √19 cm.
Let's substitute these values into the equation and solve for c:
c^2 = (2 cm)^2 + (√19 cm)^2 - 2 * 2 cm * √19 cm * cos(120°)
c^2 = 4 cm^2 + 19 cm - 4 cm * √19 cm * (-0.5)
c^2 = 4 cm^2 + 19 cm + 2 cm * √19 cm
c^2 = 4 cm^2 + 19 cm + 2 cm * (√19 cm)
c^2 = 4 cm^2 + 19 cm + 2 cm * (√19 cm)
c^2 ≈ 29.79 cm^2
Taking the square root of both sides gives us:
c ≈ √(29.79 cm^2)
c ≈ 5.457 cm
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A company has monthly flxed costs of $8,600. The production cost of each item is $18 and each item sells for $32. Let x be the number of items that are produced and soid. Determine each of the following functions. Enter all answers below in slope-intercept form, using exact numbers. (a) What is the company's monthly cost function? c(x)= (b) What is the company's monthly revenue function? P(x)= (c) What is the company's monthly profit function? p(x)=
(a) The company's monthly cost function is c(x) = 8,600 + 18x.
(b) The company's monthly revenue function is P(x) = 32x.
(c) The company's monthly profit function is p(x) = 14x - 8,600.
(a) The company's monthly cost function can be determined by adding the fixed costs to the variable costs, which are the production cost per item multiplied by the number of items produced. The fixed costs are $8,600 and the production cost per item is $18. Therefore, the monthly cost function is:
\[c(x) = 8,600 + 18x\]
(b) The company's monthly revenue is obtained by multiplying the selling price per item by the number of items sold. The selling price per item is $32. Therefore, the monthly revenue function is:
\[P(x) = 32x\]
(c) The company's monthly profit can be calculated by subtracting the cost function from the revenue function. Therefore, the monthly profit function is:
\[p(x) = P(x) - c(x) = 32x - (8,600 + 18x) = 14x - 8,600\]
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1) Solve the following linear equation: X/5 +(2+x)/2 = 1
2) Solve the following equation: x/5+(2+x)/2 < 1
3) A university club plans to raise money by selling custom printed t-shirts. They find that a printer charges $500 for creating the artwork and $4 per shirt that is printed. If they sell the shirts for $20 each, how many shirts must they make and sell to break even.
4) Find the domain of the function: y = (2+x)/(x-5)
5) Find the domain of the function: y = square root(x-5)
1. The given linear equation: X/5 + (2+x)/2 = 1
To solve the equation, we can simplify and solve for x:
Multiply every term by the common denominator, which is 10:
2x + 5(2 + x) = 10
2x + 10 + 5x = 10
Combine like terms:
7x + 10 = 10
Subtract 10 from both sides:
7x = 0
Divide both sides by 7:
x = 0
Therefore, the solution to the equation is x = 0.
2. To solve the inequality, we can simplify and solve for x:
Multiply every term by the common denominator, which is 10:
2x + 5(2 + x) < 10
2x + 10 + 5x < 10
Combine like terms:
7x + 10 < 10
Subtract 10 from both sides:
7x < 0
Divide both sides by 7:
x < 0
Therefore, the solution to the inequality is x < 0.
3.To break even, the revenue from selling the shirts must equal the total cost, which includes the cost of creating the artwork and the cost per shirt.
Let's assume the number of shirts they need to sell to break even is "x".
Total cost = Cost of creating artwork + (Cost per shirt * Number of shirts)
Total cost = $500 + ($4 * x)
Total revenue = Selling price per shirt * Number of shirts
Total revenue = $20 * x
To break even, the total cost and total revenue should be equal:
$500 + ($4 * x) = $20 * x
Simplifying the equation:
500 + 4x = 20x
Subtract 4x from both sides:
500 = 16x
Divide both sides by 16:
x = 500/16
x ≈ 31.25
Since we cannot sell a fraction of a shirt, the university club must sell at least 32 shirts to break even.
4. The function: y = (2+x)/(x-5)
The domain of a function represents the set of all possible input values (x) for which the function is defined.
In this case, we need to find the values of x that make the denominator (x-5) non-zero because dividing by zero is undefined.
Therefore, to find the domain, we set the denominator (x-5) ≠ 0 and solve for x:
x - 5 ≠ 0
x ≠ 5
The domain of the function y = (2+x)/(x-5) is all real numbers except x = 5.
5. The function: y = √(x-5)
The domain of a square root function is determined by the values inside the square root, which must be greater than or equal to zero since taking the square root of a negative number is undefined in the real number system.
In this case, we have the expression (x-5) inside the square root. To find the domain, we set (x-5) ≥ 0 and solve for x:
x - 5 ≥ 0
x ≥ 5
The domain of the function y = √(x-5) is all real numbers greater than or equal to 5.
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Solve the system if possible by using Cramer's rule. If Cramer's rule does not apply, solve the system by using another method. Write all numbers as integers or simplified fractions. 10x+4y=2 -6x+2y=
The solution of the given system of equations is, x = 0 and y = 1/6.
Given system of equations,10x+4y=2 ...(1)-6x+2y= ...(2)Solve the system if possible by using Cramer's rule.Cramer's Rule:Cramer's rule is used to solve a system of linear equations in variables. Consider a system of n variables and n equations. The equations can be written in the form of AX = B, where A is the matrix of coefficients, X is the column matrix of variables, and B is the column matrix of constants. The Cramer's rule can be defined as, If the determinant of the coefficient matrix A is not zero, the system of equations has a unique solution, and it is given byx = Dx/DA where Dx is the determinant of the matrix obtained from A by replacing the column of variables with the column matrix B. Similarly, y and z are given by, y = Dy/DA and z = Dz/DA where Dy and Dz are the determinants obtained from the matrix A by replacing the second and third columns with the column matrix B, respectively.The given system of equation is,10x + 4y = 2 ...(1)-6x + 2y = 0 ...(2)
The coefficients of the given equations can be written in the matrix form as, A = [10, 4; -6, 2]The column matrix of variables is, X = [x; y]The column matrix of constants is, B = [2; 0]The determinant of the matrix A is,DA = |A| = (10)(2) - (4)(-6) = 20 + 24 = 44Since the determinant of the matrix A is not equal to zero, the system of equations has a unique solution. The solution of the system can be obtained by the Cramer's rule as, x = Dx/DAd = |-6, 2; 0, 0| = (0)(0) - (2)(0) = 0Dy = |10, 2; -6, 0| = (10)(0) - (2)(-6) = 12Therefore, x = 0/44 = 0y = Dy/DAd = 12/44 = 3/11Therefore, the solution of the given system of equations is,x = 0y = 3/11If Cramer's rule does not apply, solve the system by using another method. Here, both the given equations can be written in slope-intercept form as,y = (-5/13)x + 1/6 ...(1)y = 3x ...(2)The equations can be graphed as below,Intersecting point is (0, 1/6)Therefore, the solution of the given system of equations is, x = 0 and y = 1/6.
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During a restaurant promotion, 3 out of every 25 customers receive a $10 coupon to use on their next visit. If there were 150 customers at the restaurant today, what was the total value of the coupons that were given out?.
Answer:
Step-by-step explanation:
First we need to know how many customers in total received a coupon the day that there were 150 customers.
If for each 25 customers, 3 received a coupon. 0.12 of customers received a coupon ([tex]\frac{3}{25}[/tex] = 0.12)
You can multiply this value by 150 to get 0.12 x 150 = 18 people
Another way you can think about this is 150/25 = 6 and 6 x 3 = 18 people
Now that we know how many people received coupons, we need to find the monetary value of these coupons. To do this, we multiply 18 by $10. Therefore, the total value of the coupons that were given out was $180.
Answer: $180
Answer:
18 people
Step-by-step explanation:
3/25 = x/150
3 times 150 / 25
= 450/25
= 18 people
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Let W= computers with Winamp), with ∣W∣=143, R={ computers with RealPlayer }, with ∣R∣=70, and C={ computers with a CD writer }, with ∣C∣=33. Also, let ∣W∩C∣=20,∣R∩C∣=7, and ∣W∩R∣=28, and let 193 machines have at least one of the three. How many computers have Winamp, RealPlayer, and a CD writer?
According to the given information, there are 2 computers that have Winamp, RealPlayer, and a CD writer among the total of 193 machines with at least one of the three applications.
Let's solve this problem using the principle of inclusion-exclusion. We know that there are a total of 193 machines that have at least one of the three software applications.
We can start by adding the number of computers with Winamp, RealPlayer, and a CD writer. Let's denote this as ∣W∩R∩C∣. However, we need to be careful not to count this group twice, so we subtract the overlapping counts: ∣W∩C∣, ∣R∩C∣, and ∣W∩R∣.
Using the principle of inclusion-exclusion, we have:
∣W∪R∪C∣ = ∣W∣ + ∣R∣ + ∣C∣ - ∣W∩R∣ - ∣W∩C∣ - ∣R∩C∣ + ∣W∩R∩C∣.
Substituting the given values, we have:
193 = 143 + 70 + 33 - 28 - 20 - 7 + ∣W∩R∩C∣.
Simplifying the equation, we find:
∣W∩R∩C∣ = 193 - 143 - 70 - 33 + 28 + 20 + 7.
∣W∩R∩C∣ = 2.
Therefore, there are 2 computers that have Winamp, RealPlayer, and a CD writer among the total of 193 machines with at least one of the three applications.
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Find all the values of x satisfying the given conditions. y=|9-2x| and y=15
The values of x are -3 and 12 that satisfy the conditions given in the question.
In order to find the values of x that satisfy the given conditions, we need to equate the two given expressions for y. Hence, we have:
|9-2x| = 15
Solving for x, we can get two possible values for x:
9 - 2x = 15 or 9 - 2x = -15
For the first equation, we have:
-2x = 6
x = -3
For the second equation, we have:
-2x = -24
x = 12
Therefore, the values of x that satisfy the given conditions are -3 and 12.
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Riley worked 14 hours more than Nasir tast menth. If Riley worked 9 hours for every 2 hours that Nasir workad, how many hours did they each work?
If Riley worked 14 hours more than Nasir last month and Riley worked 9 hours for every 2 hours that Nasir worked, then Riley worked for 18 hours and Nasir worked for 4 hours.
To find the number of hours Riley and Nasir each worked, follow these steps:
Let's assume that Nasir worked x hours of work and Riley worked y hours of work. Since Riley worked 9 hours for every 2 hours that Nasir worked, then it can be expressed mathematically as y= (9/2) * x.Since Riley worked 14 hours more than Nasir, then an equation can be formed as follows: y= 14+ x ⇒ (9/2) * x= 14+ x ⇒(7/2) * x= 14 ⇒x=4. So, Nasir worked for 4 hours.The number of hours Riley worked, y= (9/2) * x = (9/2)*4= 18 hours.Therefore, Nasir worked for 4 hours and Riley worked for 18 hours.
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Avoiding Large Errors/Overflow/Underflow (a) For x=9.8 201
and y=10.2 199
, evaluate the following two expressions that are mathematically equivalent and tell which is better in terms of the power of resisting the overflow. (i) z= x 2
+y 2
(P1.20.1a) (ii) z=y (x/y) 2
+1
(P1.20.1b) Also for x=9.8 −201
and y=10.2 −199
, evaluate the above two expressions and tell which is better in terms of the power of resisting the underflow. (b) With a=c=1 and for 100 values of b over the interval [10 7.4
,10 8.5
] generated by the MATLAB command 'logspace (7.4,8.5,100) ', PROBLEMS 65 evaluate the following two formulas (for the roots of a quadratic equation) that are mathematically equivalent and plot the values of the second root of each pair. Noting that the true values are not available and so the shape of solution graph is only one practical basis on which we can assess the quality of numerical solutions, tell which is better in terms of resisting the loss of significance. (i) [x 1
,x 2
= 2a
1
(−b∓sign(b) b 2
−4ac
)] (P1.20.2a) (ii) [x 1
= 2a
1
(−b−sign(b) b 2
−4ac
),x 2
= x 1
c/a
] (P1.20.2b) (c) For 100 values of x over the interval [10 14
,10 16
], evaluate the following two expressions that are mathematically equivalent, plot them, and based on the graphs, tell which is better in terms of resisting the loss of significance. (i) y= 2x 2
+1
−1 (P1.20.3a) (ii) y= 2x 2
+1
+1
2x 2
(P1.20.3b) (d) For 100 values of x over the interval [10 −9
,10 −7.4
], evaluate the following two expressions that are mathematically equivalent, plot them, and based on the graphs, tell which is better in terms of resisting the loss of significance. (i) y= x+4
− x+3
(P1.20.4a) (ii) y= x+4
+ x+3
1
(P1.20.4b)
To Avoid Large Errors/Overflow/Underflow :
Part (a) For x=9.8 201 and y=10.2 199,
we have the following expressions:
(i) z= x²+y²
(ii) z=y{(x/y)²+1} = y{(x²/y²)+1}
Comparing (i) and (ii) terms: In terms of power of resisting overflow,
(ii) is better because we do not have large sum of squares of x and y which are almost same order of magnitude
Part (b) With a=c=1 and for 100 values of b over the interval [tex][10^{7.4},10^{8.5][/tex] generated by the MATLAB command 'logspace(7.4,8.5,100)', w
e have the following formulas for roots of quadratic equation:
(i) [x1,x2=2a₁{(-b)±sign(b){b²-4ac}¹/²}]
(ii) [x1=2a₁{(-b)-sign(b){b²-4ac}¹/²},x2=x1c/a]
For better resistance to the loss of significance, (ii) is better. As, (ii) is designed to avoid subtracting two nearly equal numbers.
Part (c)For 100 values of x over the interval [[tex]10^{14},10^{16[/tex]],
we have the following expressions that are mathematically equivalent:
(i) y=2x²+1-1
(ii) y=2x²+1+(1/2x²)
Comparing (i) and (ii) terms: In terms of power of resisting underflow, (ii) is better because it has an additional term of larger order which can counteract the loss of significance at the small x.
Part (d) For 100 values of x over the interval [[tex]10^{(-9)},10^{(-7.4)[/tex]],
we have the following expressions that are mathematically equivalent:
(i) y=(x+4)-x/ (x+3)
(ii) y=(x+4+x)/2(x+3)
Comparing (i) and (ii) terms: In terms of power of resisting loss of significance, (ii) is better because it has a fraction with 2 instead of a difference, hence reducing the effect of the cancellation.
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Find the negation of the following statements and then determine the truth value if the universe of discourse is the set of all integers. (a) ∀x(2x−1<0) (b) ∃x(x 2 =9)
(a) The negation of the statement "∀x(2x−1<0)" is "∃x(¬(2x−1<0))", which can be read as "There exists an integer x such that 2x−1 is not less than 0."
(b) The negation of the statement "∃x(x^2≠9)" is "∀x(¬(x^2≠9))", which can be read as "For all integers x, x^2 is equal to 9."
(a) The negation of the statement "∀x(2x−1<0)" is "∃x(¬(2x−1<0))", which can be read as "There exists an integer x such that 2x−1 is not less than 0."
To determine the truth value of this negated statement when the universe of discourse is the set of all integers, we need to find a counterexample that makes the statement false. In other words, we need to find an integer x for which 2x−1 is not less than 0. Solving the inequality 2x−1≥0, we get x≥1/2.
However, since the universe of discourse is the set of all integers, there is no integer x that satisfies this condition. Therefore, the negated statement is false.
(b) The negation of the statement "∃x(x^2≠9)" is "∀x(¬(x^2≠9))", which can be read as "For all integers x, x^2 is equal to 9."
To determine the truth value of this negated statement when the universe of discourse is the set of all integers, we need to check if all integers satisfy the condition that x^2 is equal to 9. By examining all possible integer values, we find that both x=3 and x=-3 satisfy this condition, as 3^2=9 and (-3)^2=9. Therefore, the statement is true for at least one integer, and thus, the negated statement is false.
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Find the value of c that will make 100x^(2)+140x+c a perfect square trinomial
The value of c is 49,that will make 100x^(2)+140x+c a perfect square trinomial.
To make 100x² + 140x + c a perfect square trinomial, we have to add and subtract some number from 100x² + 140x.
Let us take that number as k.
Let 100x² + 140x + k = (ax + b)² be a perfect square trinomial.
Here, a and b are constants.
Expanding the above equation, we get
100x² + 140x + k = a²x² + 2abx + b²
Since this equation is true for all values of x, we can equate the corresponding coefficients on both sides of the equation.
We have a² = 100, 2ab = 140, and b² = k.
From the first equation, a = ±10, and from the second equation, b = 7.
Using these values in the third equation, we get k = b² = 7² = 49.
Thus, the value of c is 49.
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Running speed for adult men of a certain age group is known to follow a normal distribution, with mean 5.6 mies per. hour and standard deviation 1. Jim claims he run faster than 80% of adult men in this age group. What speed would he need to be able to run for this to be the case? Gwe your answer accurate 10 two digits past the decimal point What is the srobabilify that a tandomiy seiected man from the certain age group funs alower than 71 mph.? 0.0332 6. 0068 c. 01760 d. 05 -. 0.6915
The probability that a randomly selected man from the certain age group runs slower than 7.1 miles per hour is 0.9332.
Given: Running speed for adult men of a certain age group is known to follow a normal distribution, with mean 5.6 miles per hour and standard deviation
To find: What speed would he need to be able to run for this to be the case?
First we find the z score corresponding to 80% probability.
Using standard normal table, we get the corresponding z-score for 0.8 is 0.84.
z = (x - μ)/ σ
0.84 = (x - 5.6) / 1
x - 5.6 = 0.84
x = 5.6 + 0.84
x = 6.44 miles per hour (2 decimal places)
Therefore, Jim needs to run at least 6.44 miles per hour to be able to run faster than 80% of adult men in this age group.
Probability that a randomly selected man from the certain age group runs slower than 7.1 miles per hour is:
P (x < 7.1) = P (z < (7.1 - 5.6) / 1) = P (z < 1.5) = 0.9332 (using standard normal table)
Hence, the probability that a randomly selected man from the certain age group runs slower than 7.1 miles per hour is 0.9332.
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After a 12% discount, a calculator was sold for $16.50. What was its regular price?
The regular price of the calculator was approximately `$18.75`.
Let's denote the regular price by `x`.
The calculator is sold at a discount of `12%`, so the price is `100% - 12% = 88%` of the regular price.
Therefore, we have:0.88x = 16.5.
Solving for `x`:x = 16.5/0.88x ≈ $18.75.
So the regular price of the calculator was approximately `$18.75`.
Therefore, after a `12% discount`, the calculator was sold for `$16.50`.
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Dawn spent $26. 50,
including sales tax on 4 books and 3 folders.
The books cost $5. 33 each and the total sales tax
was $1. 73. Fill in the table with the correct cost
of each item.
The cost of each item is as follows: Each book costs $5.33, and each folder costs $1.73.
We know that Dawn spent a total of $26.50, including sales tax, on the books and folders. This means that the cost of the books and folders, before including sales tax, is less than $26.50.
Each book costs $5.33. Since Dawn bought 4 books, the total cost of the books without sales tax can be calculated by multiplying the cost of each book by the number of books:
=> $5.33/book * 4 books = $21.32.
We are also given that the total sales tax paid was $1.73. This sales tax is calculated based on the cost of the books and folders.
To determine the sales tax rate, we need to divide the total sales tax by the total cost of the books and folders:
=> $1.73 / $21.32 = 0.081, or 8.1%
To find the cost of each item, we need to allocate the total cost of $26.50 between the books and the folders. Since we already know the total cost of the books is $21.32, we can subtract this from the total cost to find the cost of the folders:
=> $26.50 - $21.32 = $5.18.
Finally, we divide the cost of the folders by the number of folders to find the cost of each folder:
=> $5.18 / 3 folders = $1.7267, or approximately $1.73
So, the cost of each item is as follows: Each book costs $5.33, and each folder costs $1.73.
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How many four person committees are possible from a group of 9 people if: a. There are no restrictions? b. Both Tim and Mary must be on the committee? c. Either Tim or Mary (but not both) must be on the committee?
In either case, there are a total of 35 + 35 = 70 possible four-person committees when either Tim or Mary (but not both) must be on the committee.
a. If there are no restrictions, we can choose any four people from a group of nine. The number of four-person committees possible is given by the combination formula:
C(9, 4) = 9! / (4! * (9 - 4)!) = 9! / (4! * 5!) = 9 * 8 * 7 * 6 / (4 * 3 * 2 * 1) = 126
Therefore, there are 126 possible four-person committees without any restrictions.
b. If both Tim and Mary must be on the committee, we can select two more members from the remaining seven people. We fix Tim and Mary on the committee and choose two additional members from the remaining seven.
The number of committees is given by:
C(7, 2) = 7! / (2! * (7 - 2)!) = 7! / (2! * 5!) = 7 * 6 / (2 * 1) = 21
Therefore, there are 21 possible four-person committees when both Tim and Mary must be on the committee.
c. If either Tim or Mary (but not both) must be on the committee, we need to consider two cases: Tim is selected but not Mary, and Mary is selected but not Tim.
Case 1: Tim is selected but not Mary:
In this case, we select one more member from the remaining seven people.
The number of committees is given by:
C(7, 3) = 7! / (3! * (7 - 3)!) = 7! / (3! * 4!) = 7 * 6 * 5 / (3 * 2 * 1) = 35
Case 2: Mary is selected but not Tim:
Similarly, we select one more member from the remaining seven people.
The number of committees is also 35.
Therefore, in either case, there are a total of 35 + 35 = 70 possible four-person committees when either Tim or Mary (but not both) must be on the committee.
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Prove: #1⋅a(−b)=−(ab)
#2⋅(−a)(−b)=ab
Answer: 1. a(−b)=−(ab)
2⋅(−a)(−b)=ab
Step-by-step explanation: -a = (-1)a and
-b = (-1)b.
1. a(-b) = a(-1)b
by using basic properties of real numbers, commutative axiom of Multiplication and the associate axiom,
= (-1)ab
= -(ab)
2. (-a)(-b) = ab
by using a commutative axiom of Multiplication, and the associate axiom,
(-a)(-b) = (-1)(a)(-1)(b) = (-1)(-1)(a)(b)
by multiplication and associate law,
(-a)(-b)= ab
hence proved.
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suppose a tank contains 500 L of water with 20 kg of salt in it at the beginning. salt water of concentration 4 kg/L is pouring in at a rate of 4 L/min. well-mixed salt water is flowing out at a rate of 5 L/min. find the amount of salt in the tank after one hour.
Calculating this expression, we find that the amount of salt in the tank after one hour is approximately 79.72 kg.
To solve this problem, we need to consider the rate of change of the amount of salt in the tank over time.
Let's denote the amount of salt in the tank at time t as S(t), measured in kilograms.
The rate of change of salt in the tank can be determined by considering the inflow and outflow of salt.
The rate of salt flowing into the tank is given by the concentration of the saltwater pouring in (4 kg/L) multiplied by the rate of inflow (4 L/min), which is 16 kg/min.
The rate of salt flowing out of the tank is given by the concentration of the saltwater in the tank (S(t)/V(t) kg/L) multiplied by the rate of outflow (5 L/min), where V(t) represents the volume of water in the tank at time t.
Given that the volume of water in the tank is constant at 500 L, we can write V(t) = 500 L.
Therefore, the rate of salt flowing out of the tank is (S(t)/500) * 5 kg/min.
Putting it all together, we can set up the following differential equation for the amount of salt in the tank:
dS/dt = 16 - (S(t)/500) * 5
Now we can solve this differential equation to find S(t) after one hour (t = 60 minutes) with the initial condition S(0) = 20 kg.
Using an appropriate method for solving differential equations, we find:
S(t) = 80 - 3200 * e*(-t/100)
Plugging in t = 60, we get:
S(60) = 80 - 3200 * e*(-60/100)
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