From a club of 20 people, in how many ways can a group of three members be selected to attend a conference?​

Answers

Answer 1
Answer:    1140

=============================================================

Reason:

There are 20 ways to pick the first person, 19 for the next, and 18 for the last. We count down by one each time we fill up a slot since we cannot reselect any person more than once.

If order mattered, then we'd have 20*19*18 = 6840 permutations.

However, order does not matter because no member has a special seat or role. The individual members don't matter and instead it's all about the group.

Notice that for any group of 3 people, there are 3*2*1 = 6 ways to arrange such individuals. We have to divide by 6 to go from 6840 permutations to 6840/6 = 1140 combinations.

-------------------------

Here's a more formulaic approach using the nCr combination formula.

Plug in n = 20 and r = 3

[tex]n C r = \frac{n!}{r!(n-r)!}\\\\20 C 3 = \frac{20!}{3!*(20-3)!}\\\\20 C 3 = \frac{20!}{3!*17!}\\\\20 C 3 = \frac{20*19*18*17!}{3!*17!}\\\\ 20 C 3 = \frac{20*19*18}{3!}\\\\ 20 C 3 = \frac{20*19*18}{3*2*1}\\\\ 20 C 3 = \frac{6840}{6}\\\\ 20 C 3 = 1140\\\\[/tex]


Related Questions

if p + 2q = 40 find Q when p = 16​

Answers

hello!

Plug in the value of p:-

16+2q=40

Subtract 16 from both sides:-

2q=40-16

2q=24

Divide both sides by 2:-

q=12 ✓

note:-

Hope everything is clear; if you need any clarification/explanation, kindly let me know, and I'll comment and/or edit my answer :)

Three students are sitting in a playground to make a circular path. They are sitting on the circumference, the co-ordinates of their position on the circle are (1, 2), (3, 4) and (3, 2). Find the co-ordinates of the point equidistant from their position. Also, find the equation of the locus.​

Answers

The coordinates of the point equidistant from their position is C(x,y) = (2, 3) and the equation of the locus is (x - 2)² + (y - 3)² = 2.

How to derive the equation of the circunference associated with a playground

The center is the point that is equidistant to every point on the circumference. First, we need to determine the coefficients of the general equation of the circle, whose form is described below:

x² + y² + D · x + E · y + F = 0   (1)

We need three distinct points of the circumference to determine one solution.

If we know that (x₁, y₁) = (1, 2), (x₂, y₂) = (3, 4) and (x₃, y₃) = (3, 2), then the system of linear equations is:

D + 2 · E + F = -5   (2)

3 · D + 4 · E + F = - 25   (3)

3 · D + 2 · E + F =  - 13   (4)

The solution of the linear system is D = - 4, E = - 6 and F = 11.

Now we proceed to transform the expression into its standard form by completing the squares:

x² + y² - 4 · x - 6 · y + 11 = 0

( - 4 · x + 4) + (y² - 6 · y + 9) - 2 = 0

(x - 2)² + (y - 3)² = 2

The coordinates of the point equidistant from their position is C(x,y) = (2, 3) and the equation of the locus is (x - 2)² + (y - 3)² = 2.

To learn more on circumferences, we kindly invite to check this verified question: https://brainly.com/question/4268218

i need help 100 points for a question

Answers

Answer:

34.28 ft

Step-by-step explanation:

Find the length of semicircle

C = πd, circumference of circleC/2 = πd/2 = 3.14*4/2 = 6.28 ft

Find the perimeter

P = 4 + 6.28 + 2*12 = 34.28 ft

For rectangle

L=12B=4

Perimeter:-

2(L+B)2(12+4)2(16)32ft

For semicircle:-

radius=r=4/2=2ft

Perimeter:-

πr2π6.28ft

Total:-

6.28+32-438.28-434.28ft

Adam earns $36 for every four hours of work how long will it take him to earn $144

Answers

Answer:

It will take 16 hours to earn $144.

Step-by-step explanation:

If Adam earns $36 in 4 hours,

36 = 4k

k = 9

Therefore, expression for total earnings will be,

y = 9x

a). For y = $144,    144 = 9x      x = 16 hours

6. Sam scored 12 points on a math quiz, and he scored 3 points fewer than Alicia. Write an
equation for this situation, and find Alicia's score.

Answers

x - 3 = 12
x = 12 + 3
x = 15

1 point
2. Three boards are unloaded into the factory.
А
B
С
Board A is three times the length of board C, plus 5 inches. Board B is two
times the length of board C, plus 3 inches. The total length of all three boards
is 104 inches. How long is each board?
Your answer
??

Answers

Each side of the board would have to be at least 36

60 = y-3 divided by 10

Answers

Answer:

y  = 60.3

Step-by-step explanation:

Park
Avenue
Describe the lines that intersect at Park Avenue and Hawthome Boulevard. Explain.

Answers

Answer:

make it clearer

Step-by-step explanation:

What are the solution to the equation below? 4x^2+ 9 = 25

Answers

that is the complete answer to the question

Enter the solution (x, y) to the system of equations shown.


y=4x−3
y=−x−13

Answers

Answer:

x=-2

y=-11

Step-by-step explanation:

4x-3=-x-13

5x-3=-13

5x=-10

x=-2

y=4(-2)-3

y=-11

Can yo solve this ones, please? in adittion, can you put answers and the process. The topic are area down the curve

Answers

1) The net area between the two functions is 2.

2) The net area between the two functions is 4/3.

3) The net area between the two functions is 17/6.

4) The net area between the two functions is approximately 1.218.

5) The net area between the two functions is 1/2.

How to determine the area between two functions by definite integrals

The area between the two curves is determined by definite integrals for a interval between two values of x. A general formula for the definite integral is presented below:

[tex]A = \int\limits^{b}_{a} {[f(x) - g(x)]} \, dx[/tex]   (1)

Where:

a - Lower limitb - Upper limitf(x) - "Upper" functiong(x) - "Lower" function

Now we proceed to solve each integral:

Case I - [tex]f(x) = \sqrt{x}[/tex] and [tex]g(x) = x^{2}[/tex]

The lower and upper limits between the two functions are 0 and 1, respectively. The definite integral is described below:

[tex]A = \int\limits^1_0 {x^{0.5}} \, dx - \int\limits^1_0 {x^{2}} \, dx[/tex]

[tex]A = 2\cdot (1^{1.5}-0^{1.5})-\frac{1}{3}\cdot (1^{3}-0^{3})[/tex]

[tex]A = 2[/tex]

The net area between the two functions is 2. [tex]\blacksquare[/tex]

Case II - [tex]f(x) = -4\cdot x[/tex] and [tex]g(x) = x^{2}+3[/tex]

The lower and upper limits between the two functions are -3 and -1, respectively. The definite integral is described below:

[tex]A = - 4 \int\limits^{-1}_{-3} {x} \, dx - \int\limits^{-1}_{-3} {x^{2}} \, dx - 3 \int\limits^{-1}_{-3}\, dx[/tex]

[tex]A = -2\cdot [(-1)^{2}-(-3)^{2}]-\frac{1}{3}\cdot [(-1)^{3}-(-3)^{3}] -3\cdot [(-1)-(-3)][/tex]

[tex]A = \frac{4}{3}[/tex]

The net area between the two functions is 4/3. [tex]\blacksquare[/tex]

Case III - [tex]f(x) = x^{2}+2[/tex] and [tex]g(x) = -x[/tex]

The definite integral is described below:

[tex]A = \int\limits^{1}_{0} {x^{2}} \, dx + 2\int\limits^{1}_{0}\, dx + \int\limits^{1}_{0} {x} \, dx[/tex]

[tex]A = \frac{1}{3}\cdot (1^{3}-0^{3}) + 2\cdot (1-0) +\frac{1}{2}\cdot (1^{2}-0^{2})[/tex]

[tex]A = \frac{17}{6}[/tex]

The net area between the two functions is 17/6. [tex]\blacksquare[/tex]

Case IV - [tex]f(x) = e^{-x}[/tex] and [tex]g(x) = -x[/tex]

The definite integral is described below:

[tex]A = \int\limits^{0}_{-1} {e^{-x}} \, dx+ \int\limits^{0}_{-1} {x} \, dx[/tex]

[tex]A = -(e^{0}-e^{1}) + \frac{1}{2}\cdot [0^{2}-(-1)^{2}][/tex]

[tex]A \approx 1.218[/tex]

The net area between the two functions is approximately 1.218. [tex]\blacksquare[/tex]

Case V - [tex]f(x) = \sin 2x[/tex] and [tex]g(x) = \sin x[/tex]

This case requires a combination of definite integrals, as f(x) may be higher that g(x) in some subintervals. The combination of definite integrals is:

[tex]A = \int\limits^{\frac{\pi}{3} }_0 {\sin 2x} \, dx - \int\limits^{\frac{\pi}{3} }_{0} {\sin x} \, dx + \int\limits^{\frac{\pi}{2} }_{\frac{\pi}{3} } {\sin x} \, dx -\int\limits^{\frac{\pi}{2} }_{\frac{\pi}{3} } {\sin 2x} \, dx[/tex]

[tex]A = -\frac{1}{2}\cdot (\cos \frac{2\pi}{3}-\cos 0)+(\cos \frac{\pi}{3}-\cos 0 ) -(\cos \frac{\pi}{2}-\cos \frac{\pi}{3} )+\frac{1}{2}\cdot (\cos \pi-\cos \frac{2\pi}{3} )[/tex]

[tex]A = \frac{1}{2}[/tex]

The net area between the two functions is 1/2. [tex]\blacksquare[/tex]

To learn more on definite integrals, we kindly invite to check this verified question: https://brainly.com/question/14279102

pls help me uwuwuwuuwuwuww

Answers

Answer:

128

6

12

48

Step-by-step explanation:

in addition to the diagram, which statement is necessary to prove that the two triangles are congruent by the SAS criterion?
A . AC=DE
B. m C.BC=EF
D. m

Answers

Answer:

BC = FE

Step-by-step explanation:

given ,

BA = FD and the measure of angle ABC = the measure of angle DFE

If we have BC = FE then according to the SAS criterion the two triangles are congruent

What are the zeros of the function below?
F(x) = 8x(x-6)/(x+2)(x+9)

Answers

Answer:

x = 0, 6

Step-by-step explanation:

8x(x-6) = 0

x = 0, 6

Select ALL of the expressions that are equivalent to 4√5.

A. 2√20
B. 6^1/2-5^1/2
c. 3*5^1/2+5^1/2
D.4*5^1/2
E.2√10
F.3*5^1/2

Answers

Answer:

A, C, D


All 3 of those simplfiy to 4√5

QUESTION 1 Which one of the following is an ordered pair? O {-3,5} O (2, 4,0) 0 (0, 6) 0 1,3​

Answers

The ordered pair here in the given is (0,6) because an ordered pair is compose of two coordinates which are the abscissa and ordinate with parenthesis.


Which economic system has no government involvement in the market?
a capitalism
.. communism
C. socialism
l. No economic system is free from government involvement.
Please select the best answer from the choices provided

Answers

Answer: I.

Step-by-step explanation:

Capitalism is clearly not the answer. Capitalist governments such as America have their fingers into the economic trading.

Socialism and Communism sound plausible, but Communism is giving people money by their work, and Socialism is everything is owned by the public. Both still involve themselves in markets, so the answer is I

Answer:

d.

No economic system is free from government involvement.

Step-by-step explanation:

Simplify the expression. 16 • 4–4

a)256
b)–256
c)1/16
d)–4,096

Answers

Answer: C) 1/16

Hope this helps :)

Find the distance between the two points in simplest radical form.
(3,9) and (-2,4)

Answers

Explaination :

Here we would be using distance formula to calculate the distance between those two points.

Points are,

(3 , 9)(-2 , 4)

Distance Formula :

[tex]\huge \large \boxed{\sf{{d \: = \: \sqrt{(x _{2} - x _{1}) {}^{2} \: + \: (y _{2} - y _{1}) {}^{2} }}}} \: \red\bigstar[/tex]

We have :

x1 = 3

x2 = -2

y1 = 9

y2 = 4

Substituting the values :

Refer the attachment.Additional Information :

Centroid of a triangle :-

[tex]\boxed{ \sf{Centroid \: = \: \dfrac{x_1 \: + \: x_2 \: + \: x_3}{3} }} \: \pink\bigstar[/tex]

Midpoint of two points:-

[tex]\boxed{ \sf{M \: = \: \dfrac{x_1 \: + \: x_2 }{2} \: , \: \dfrac{y_1 \: + \: y_2 }{2}}} \: \pink\bigstar[/tex]

What is the area of the obtuse triangle given below?
6, 18

Answers

Answer:

54

Step-by-step explanation:

A = 1/2 bh

A = 1/2 (6)(18)

A = 1/2 (108)

A = 54

Area of the Obtuse triangle whose measures are 6 and 18 is 54 square units.

What is Triangle?

A triangle is a three-sided polygon that consists of three edges and three vertices.

We need to find the area of the obtuse triangle whose base is six units and height is eighteen 18 units.

A triangle whose any one of the angles is an obtuse angle or more than 90° is called Obtuse.

The area of triangle is 1/2×Base×Height

Half base times of height

Area of triangle=1/2×6×18

=54 square units

Area is 54 square units.

Hence, Area of the Obtuse triangle whose measures are 6 and 18 is 54 square units.

To learn more on Triangles click:

https://brainly.com/question/2773823

#SPJ7

PLEASE HELPPPPPPPPPPPPPPPPPPPPPPPPPPP
Consider this dilation.



(a) Is the image of the dilation a reduction or an enlargement of the original figure? Explain.
(b) What is the scale factor? Explain and show your work.

ANSWER BOTH PARTS YOU MAY GET EXTRA POINTS!

Answers

Step-by-step explanation:

1) if the initial figure ABCD, then the figure A'B'C'D' is reduction of the initial one.

2) the scale factor is 0.5: the ratio of all the corresponded coordinates is 2:1 [D(8;4) - D'(4;2); C(4;0)-C'(2;0); B(0;-2)-B'(0;-1) and A(-4;4)-A'(-2;2)].

Mark the quadrilaterals ABcD and A'B'C'D'

The image is reduced in size hence it's reduction

Take 2 sides two calculate scale factor

AD=12unitsA'D'=6units

Scale factor:-

6/121/2

meter and Area
1
Casey wants to put new carpet in her bedroom. A drawing of Casey's room is below. It consists of two sections: a square and a
rectangle
The rectangular section has the same width as the square section, but wice the length. If one side of the square section measures 3
yards, how many square yards of carpet should Casey buy for her room?
A 36 square yards
OB 24 square yards
OC 18 square yards
D. 27 square yards

Answers

Answer:

18 square yards

Step-by-step explanation:

because if you do 3x3 twice then add the two numbers you get you will get 18.

I WILL GIVE 20 POINTS TO THOSE WHO ANSWER THIS RIGHT NOOOO SCAMS AND EXPLAIN WHY THAT IS THE ANSWER

Answers

Answer:

160

Step-by-step explanation:

FEJ angle is the large angle and the number in red shows how big it is. Remember the whole thing is 180 degrees.

Ok so the answer is
160°
It is an obtuse angle because it is greater than 90°

Hope this helps :)

=) A student is taking a standardized test
consisting of multiple choice questions for
which there are five options for each question.
Four points are awarded for each correct
answer, but the student loses 2 points for an
incorrect answer. Questions left blank neither
receive nor lose points. Is it in the student's
best interest to guess?

Answers

Answer:

in this problem. Not that the total number of ways of taking one or more alternative out of ...

Step-by-step explanation:

Answer:

No.

Step-by-step explanation:

Well, honestly not sure how to solve this but I'll try.

Each correct answer is giving 4 points but the probability to choose the correct one is 1/5

Each incorrect one gives -2 points and the chance to pick a wrong answer is 4/5.

Obviously, the chance to lose points is more. But is taking the risk and guessing worth it? Well, it depends on how many points the correct answer gives. If it makes up for the possible loss of points, then it is in his interest to guess, otherwise he will end up losing more than they win.

If we sum the two chances to find averagely how many points the student will get, then I guess that would be the correct answer:

4(1/5) + (-2)(4/5) = 4/5 - 8/5 = -4/5

He will get averagely -4/5 points, so I believe it isn't in his interest. It means that the points he gets don't make up for the possible loss of points if you choose answers randomly. (Wow, I'm glad teachers don't do this on tests 0_0)

This is my theory though, not sure how to go for solving this, just thinked logically. I hope this helps, but don't trust me and copy paste my answer on your test or whatever. Think if this is correct first because I'm not sure

Help picture below problem 12

Answers

Answer:

isosceles triangle is shown in fig

Find the sum of the first 21 terms of the arithmetic progression.
−7, −11, −15, . . .

Answers

We are given with an AP (Arithmetic Progression) with first term being -7, and the common difference being the difference between any succeding term from any term and the term itself, so common difference = -11 - (-7) = -11 + 7 = -4, so now before finding the sum of 21 terms, let's recall that ;

[tex]{\boxed{\bf{S_{n}=\dfrac{n}{2}\{2a+(n-1)d\}}}}[/tex]

Where, d is the common difference, a is the first term, and n is the number of terms and [tex]{\bf S_n}[/tex], being the sum of n terms, so putting all the values in the formula, we will have ;

[tex]{:\implies \quad \sf S_{21}=\dfrac{21}{2}\{2\times -7+(21-1)-4\}}[/tex]

[tex]{:\implies \quad \sf S_{21}=\dfrac{21}{2}(-8+20\times -4)}[/tex]

[tex]{:\implies \quad \sf S_{21}=\dfrac{21(-8-80)}{2}}[/tex]

[tex]{:\implies \quad \sf S_{21}=\dfrac{21(-88)}{2}}[/tex]

[tex]{:\implies \quad \sf S_{21}=-21\times 44}[/tex]

[tex]{:\implies \quad \boxed{\bf{S_{21}=-924}}}[/tex]

Over the last 16 years Johanna saved some of her pay each month. She now has $46,000. She decides to invest some
of it at 5.25% annual interest and the rest at 3.75% annual interest. After one year, her total interest earned from both
accounts is $2001. How much did she invest in each account? (Clearly label which amount is for which account in
your answer.

Answers

The amount invested in the account that gives a 5.25% interest is  $18400.

The amount invested in the account that gives a 3.75% interest is 27600.

What are the linear equations that represent this question?

0.0525a + 0.0375b = 2001 equation 1

a + b = 46000 equation 2

Where:

a = amount invested in the account that gives a 5.25% interest

b = amount invested in the account that gives a 3.75% interest

What is the amount invested in the account that gives a 3.75% interest?

Multiply equation 2 by 0.0525

0.0525a + 0.0525b = 2415 equation 3

Subtract equation 1 from equation 3

414 = 0.015b

b = 27600

What is the amount invested in the account that gives a 5.25% interest ?

Subtract 27600 from 46000

46000  27600 = $18400

To learn more about simultaneous equations, please check: https://brainly.com/question/25875552

I am a polygon that has two pairs of opposite sides that are parallel what am I

Answers

A Parallelogram because it is a quadrilateral with 2 pairs of parallel sides!

Using the formula S = P(1 + r)t, where P is the original principal, r is the annual interest rate, and t is the number of years, what is the investment savings, S, if P = $14,500.00, r = 7.5%, and t = 5 years?

Answers

[tex]~~~~~~ \textit{Savings Earned Amount} \\\\ S=P\left(1+r\right)^{t} \quad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{original amount deposited}\dotfill &\$14500\\ r=rate\to 7.5\%\to \frac{7.5}{100}\dotfill &0.075\\ t=years\dotfill &5 \end{cases} \\\\\\ S=14500\left(1+0.075\right)^{5}\implies S=14500(1.075)^5\implies A\approx 20816.63[/tex]

14,15,3,15,14,14,18,15,8 mean ,mode,median determine which measure of center best represenrs the data

Answers

Answer:

Mean: 12.9

Mode: 14,15

Median: 14

Step-by-step explanation:

Other Questions
Jacob would like to purchase a coat and a hat for a ski trip. the coat is $62. 75 and the hat is $14. 25. if the sales tax rate is 8%, then what will be the amount of tax on jacobs purchase? Read the passage:Oil spills from off-shore drilling and shipping are an immense threat to sea otters. Sea otters are dependent on their thick fur to keep them warm. Its unique structure traps air that insulates their bodies from the cold water. When an otter's fur is covered in oil, it can no longer keep the otter warm. This can cause hypothermia and even death. If the otter tries to clean its fur, it will ingest the oil, which is poisonous. In 1989, the Exxon Valdez hit a reef in Alaska. The ship spilled over ten million gallons of oil into the ocean. The U.S. Fish and Wildlife Service believes that anywhere from 4,000 to 10,000 otters died due to this oil spill.What point does the author make in the passage?A Oil is poisonous to all wildlife that lives in the water.B Oil spills are increasing the number of sea otter deaths.C Over the last 20 years, the number of oil spills has increased.D Sea otters have dense, thick fur to protect them from oil. The half-life of radon is 385 days. What fraction of a sample with no atoms remains at the end of 77 days? PLEASE HELP WILL GIVE 50 POINTS to the right answer Which layer makes up about two-thirds of earths mass?. help pls! brainlist if u help Dan earns 286 over the course of a five-day week. How much is that per day? Do you think that prom is a positive high school tradition or a negative one?i need to fill this out, help me! Symptoms involved with somatoform disorders feel very real to the patient but are often imagined, especially when they are unable to be diagnosed. please select the best answer from the choices provided t f PLS HELPIgnore everything above and below the simplify question Employee identification codes at a company contain 2 letters followed by 4 digits. Assume that all codes are equally likely. Identify the probability that an ID code does not contain the letter I.A. 0.9246B. 0.6567C. 0.7493D. 0.8321 How much required force is required to move a 100kg box to get it moving? Static friction is 0.5, kinetic friction is 0.3 and gravity is 9.5m/s^2 Thelma and louise drove 341 miles and used 15.5 gallons of gas how many miles did their car get per gallon of gas Summarize George orwells political beliefs in your own words brainliest if it is right In the Lewis symbol for a fluorine atom, there are __________ paired and __________ unpaired electrons. Jackson is organizing textbooks on his bookshelf. He has an English textbook, a math textbook, and a history textbook. How many different ways can he line the textbooks up on his bookshelf? What is the measure of \angle KKangle, K? Give the name (monomial, binomial, trinomial etc.) and degree of the polynomial 3x^2 + x^2 +x Simplify the sym or difference 42 - 72