The Hall family and the Cox family each used their sprinklers last summer.

The water output rate for the Hall family's sprinkler was 25 L per hour.

The water output rate for the Cox family's sprinkler was 20 L per hour.

The families used their sprinklers for a combined total of 40 hours, resulting in a total water output of 875 L.

How long was each sprinkler used?

Answers

Answer 1

The Hall family utilizes sprinklers for 15 hours compared to the 35 hours used by the Nguyen family.

How long was each sprinkler used?

The Hall family utilizes sprinklers for 15 hours compared to the 35 hours used by the Nguyen family.

Let h and n represent the amount of hours each household uses its sprinkler, the Halls and the Nguyens, respectively.

They use for a total of 50 hours, thus either h + n = 50 or h = 50 - n.

Additionally, their total water output is 1050 L, thus we may use the equation below.

35h + 15n = 1050

Replace h with h = 50 - n to get

35(50 - n) + 15n = 1050

1750 - 35n + 15n = 1050

35n - 15n = 1750 - 1050

20n = 700

34 hours, n

15 hours equal 50 h, 50 n, and 35 n.

To learn more about sprinkler refer

https://brainly.com/question/14563391

#SPJ1


Related Questions

I'm not understanding these questions, can someone help me?

Answers

Answer:

see below

Step-by-step explanation:

Sara drives 72 miles on 3.2 gallons of gas. She uses this information to calculate how many miles per gallon she can drive. Using this result, how many miles can Sara drive on 12.3 gallons of gas?

Answers

Answer:

276.75

Step-by-step explanation:

one gallon lets sara drive 22.5 miles. multiply that by 12.3 and u get 276.75 !

What number should be added to 2x3 7x2 2x so that the resulting polynomial leaves the remainder 2 when divided by 2x 3?.

Answers

4x-2 is added to the given polynomial p(x) to leave the remainder=(-2).

[tex]p(x)=2x^3-7x^2+2x\\g(x)=2x-3\\dviding. p(x) by g(x),\\ we get2x-3)2x^3-7x^2+2x(x^2-2x2x^3-3x^2- +0 -4x^2+2x-4x^2+6x+ -0 -4xq(x)=x^2-2xand, r(x)=-4x\\Now,\\According to division algorithmp\\(x)=g(x)*q(x)+r(x)2x^3-7x^2+2x=(2x-3)(x^2-2x)+(-4x)\\adding 4x-2 on both side,\\ we get\\2x^3-7x^2+2x+4x-2=(2x-3)(x^2-2x)+(-4x)+4x-22x^3-7x^2+6x-2=(2x-3)(x^2-2x)+(-2)[/tex]

4x-2 is added to the given polynomial p(x) to leave the remainder=(-2).

A polynomial is described as an expression that consists of variables, constants, and exponents, which might be mixed with the use of mathematical operations along with addition, subtraction, multiplication, and department (No division operation by a variable).

In arithmetic, a polynomial is an expression that includes indeterminates and coefficients, that entail best the operations of addition, subtraction, multiplication, and fine-integer powers of variables. An instance of a polynomial of an unmarried indeterminate x is x² − 4x + 7.

Polynomials are sums of phrases of the form k⋅xⁿ, in which okay is any wide variety and n is a positive integer. for example, 3x+2x-5 is a polynomial. advent to polynomials.

To learn more about Polynomials visit here:

brainly.com/question/11536910

#SPJ4

Complete Question:

what number must be added to[tex]2x^3-7x^2+2x[/tex] so that the resulting polynomial leaves the remainder -2 when divided by 2x-3​

What percent of the 8th graders estimated they spend less than an hour a day on social media? Round your answer to the nearest tenth of a percent.

Answers

60.4%
Hope this helps

k is a non-zero whole number. Given that 15 x 375 x k is a perfect cube, write down the smallest value of k.​

Answers

Answer:

k = 75

Step-by-step explanation:

Let's write down the prime factors of 15 and 375

15 = 3 x 5

375 = 3 x 5 x 5 x 5

So 15 x 375 = 3 x 5 x 3 x 5 x 5 x 5

= (3 x 3) x   (5 x 5 x 5) x 5

This cannot be a perfect cube

However if we multiply this by 3 x 5 x 5 we will get

(3 x 3 x ) x (5 x 5 x 5) x(5 x 5 x 5) which is a perfect cube

Since we are asked to find k such that 15 x 375 x k is a perfect cube

k = 3 x 5 x 5 = 75

ans
k = 75

k = 75
Hope this helps!

A spherical toy needs a triangular sticker (with a base of 12cm and height of 15cm) on it. The sphere has a diameter of 50cm what is the surface area not covered by the sticker?

Answers

Answer: 65.65

Step-by-step explanation:

Carry over the decimals in each number.

2) Multiply. This will give you 6,565.

3) Carry the decimal place and count how many times you moved it over. (2=1+1) Therefore, it gives you 65.65

(06.01 LC)
The distance formula can be used to prove that a triangle has (5 points)
O congruent sides
O a right angle
O parallel sides
O congruent angles

Answers

The distance formula can be used to prove that a triangle has congruent sides.

What is congruent sides?If two sides in geometry are congruent, then they have the same length. Since a square has four sides that are all the same length, it has four congruent sides. We refer to a triangle as being equilateral when its three sides are congruent. We use a slash mark to indicate the congruent sides. An equilateral triangle always has 60° angles. An isosceles triangle is one that possesses two congruent sides.Congruent sides are those in any shape that have sides that have the same length. We can say that two triangles are congruent if, for instance, all three of their sides are the same length and equal to one another. The SSS congruence rule stands for (side-side-side).

To learn more about congruent sides refer to:

https://brainly.com/question/14791175

#SPJ1

The support for a window air-conditioning unit forms a triangle and an exterior angle. What is the measure of the exterior angle?.

Answers

The measure of the exterior angle in this case is 60+60 = 120 degrees.

What is exterior angle ?

An exterior angle of a polygon is an angle formed between one side of the polygon and a line extended from the endpoint of the opposite side. An exterior angle can be formed by standing outside of the polygon and looking at it.

In a triangle, the measure of an exterior angle is equal to the sum of the measures of the two interior angles opposite to it. In any convex polygon, the sum of the measures of the exterior angles is always 360 degrees.

The support for a window air-conditioning unit forms a triangle. A triangle is a three-sided polygon, and all the interior angles in a triangle add up to 180 degrees. Therefore, the measure of each interior angle of a triangle is (180/3) = 60 degrees.

An exterior angle of a triangle is the angle formed between one side of the triangle and a line extended from the endpoint of the opposite side. In a triangle, the measure of an exterior angle is equal to the sum of the measures of the two interior angles opposite to it.

Therefore, the measure of the exterior angle in this case is 60+60 = 120 degrees.

To learn more about exterior angle visit : brainly.com/question/28835566

#SPJ4

consider the function f(x) = -2 (x-3) (x + 1)

Answers

The graph for the points (-1, 0), (0, 6), (1, 8), (2, 6) and (3, 0) is plotted below.

What is the function?

Functions are the fundamental part of the calculus in mathematics. The functions are the special types of relations. A function in math is visualized as a rule, which gives a unique output for every input x.

The given function is f(x)=-2(x-3)(x+1).

Graph the parabola using the direction, vertex, focus, and axis of symmetry.

Direction: Opens Down

Vertex: (1,8)

Focus: (1,63/8)

Axis of Symmetry: x=1

Directrix: y=65/8

Plot the points (-1, 0), (0, 6), (1, 8), (2, 6) and (3, 0).

Therefore, graph for the points (-1, 0), (0, 6), (1, 8), (2, 6) and (3, 0) is plotted below.

To learn more about the function visit:

https://brainly.com/question/28303908.

#SPJ1

Please help me with this Geometry Question

Answers

The value of x from the given figure is 12 units.

What are similar triangles?

Two triangles are similar if the angles are the same size or the corresponding sides are in the same ratio. Either of these conditions will prove two triangles are similar.

From the given figure,

Consider ΔADC and ΔABC,

∠C=∠C (Reflex property)

AC=AC (Reflex property)

∠BAC=∠CDA=90°

By AA similarity, ΔADC ~ ΔABC

So, AC/BC = DC/AC

x/36 = 4/x

x²=36×4

x²=144

x=12 units

Therefore, the value of x from the given figure is 12 units.

To learn more about the similar triangles visit:

https://brainly.com/question/25882965.

#SPJ1

URGENT!

find the value of x in each supplementary angle pair

Answers

Answer:

x = 14°

Step-by-step explanation:

We know that,

→ Straight line is always 180°.

Forming the equation,

→ 156° + (x + 10°) = 180°

Now the value of x will be,

→ 156° + (x + 10°) = 180°

→ x + 166° = 180°

→ x = 180° - 166°

→ [ x = 14° ]

Hence, the value of x is 14°.

The value of x in the given supplementary angle pair is 14°.

Explain the term supplementary angle?Angles that add up to 180 degrees are referred to as supplementary angles. For instance, angle 130° as well as angle 50° are complementary angles since the sum of these two angles is 180°.Two angles are classified as supplementary angles because they combine to generate a linear angle when their sum is 180 degrees. When two angles add up to 90 degrees, however, they are thought to be complimentary angles and together they make a right angle.

Then,

156 + (x + 10) = 180

166 + x = 180

x = 180 - 166

x = 14°

Thus, the value of x in the given supplementary angle pair is 14°.

To know more about the supplementary angle, here

https://brainly.com/question/12919120

#SPJ1

What is the slope of the line that passes through the points (-9,-5) and (-1,-9)

Answers

Answer:

-1/2

Step-by-step explanation:

slope is rise over run so find the difference between the y values (-9-(-5)) and divide that by the difference between the x values (-1-(-9)).

What is the value of a in the following image?

Answers

Check the picture below.

How do you use the sine rule for a triangle?.

Answers

To use the sine rule for a triangle, we will need to know at least two side lengths and the measure of the angle opposite one of those sides.

What is triangle ?

A triangle is a geometric shape that has three straight sides and three angles. Triangles are classified based on the measures of their angles and the lengths of their sides.

What is law of sine ?

The law of sines, is a mathematical relationship that relates the lengths of the sides of a triangle to the sines of its angles. Specifically, the law states that the ratio of the length of a side of a triangle to the sine of the angle opposite that side is the same for all three sides of the triangle.

It can be written as

[tex]a/sin(A) = b/sin(B) = c/sin(C) = 2R[/tex]

where R is the circumradius of the triangle.

To use the sine law to solve for an unknown side or angle in a triangle, we will need to know at least two side lengths and the measure of the angle opposite one of those sides. Once we have that information, we  can use the sine law to find the measure of the unknown angle or the length of the unknown side.

Learn more about sine rule click below :

brainly.com/question/30339234

#SPJ4

ΔRST is reflected across the line y = x to form ΔR’S’T’. Find the coordinates of the points R’, S’ and T’.
R(1,-2)
S(2,-8)
T(7,-4)

Answers

Answer:

R' ( -2,1)

S' (-8,2)

T' ( -4,7)

Step-by-step explanation:

13 Vito is training for a race. He runs 14 miles a day for
16 days. Then he runs 10 miles a day for 3 days. How
many fewer miles does he run the 3 days than the
16 days?

Answers

He ran 194 miles fewer he ran in 3 days than the 16 days run.

What is mile?

the statute mile, which is 5,280 feet long, is one example of a mile (1.609 km). The mille passus, or "thousand paces," was a unit of measurement used in ancient Rome and equaled 5,000 Roman feet.

The "old London" mile, which was eight furlongs, was first established around the year 1500. The mile at that time was equal to 5,000 feet, with the furlong being 625 feet at that time, using the larger northern (German) foot.

A statute from 1593 that confirmed the use of a shorter foot and made the length of the furlong 660 feet increased the mile by 280 feet during the reign of Queen Elizabeth I, bringing it to 5,280 feet.

The Fewer mile he ran = (16 × 14) - (3 × 10)

                                      = 194 miles

Thus, He ran 194 miles fewer he ran in 3 days than the 16 days run.

Learn more about miles

https://brainly.com/question/23245414

#SPJ1

What are the advantages of having a graphing calculator?.

Answers

The advantages of having a graphing calculator

Increases learning speed.Benefits of solving geometry problems. Advantages of accuracy.

Students from high schools or higher classes typically use graphing calculators. Furthermore, if you are a student at any of these levels, you are already familiar with the higher-levelMathematical puzzles become complex just by looking at a few numerical characters, and not all books contain the solutions to all of those puzzles. But you can avoid this situation by using a graphing calculator. One issue we frequently run into when taking a math test is not knowing whether the answer is correct or incorrect. Since a single error can alter the entire answer. The data and graphical lines must exactly match for that to be known.

To learn more about graphing calculators here

https://brainly.com/question/27554848

#SPJ4

PLEASE HELP ME I NEED TO TURN THIS IN BY TMMR!!

Answers

Answer:

[tex]\frac{4}{3}cm/s[/tex]

Step-by-step explanation:

By looking at the graph, we can use the slope formula.

[tex]slope=\frac{y^2-y^1}{x^2-x^1}[/tex]

We can substitute the point values into the equation.

[tex]\frac{16-0}{12-0}[/tex]

Then simplify.

[tex]\frac{16}{12}[/tex]

This fraction has the greatest common denominator of 4, so we will divide the numerator and the denominator.

[tex]\frac{16}{12}=\frac{4}{3}[/tex]

Therefore, the speed of the snail has a unit rate of [tex]\frac{4}{3} cm/s[/tex].

Which graph shows the solution to this inequality? 15≤−3x+6

Answers

Answer: Look below

Step-by-step explanation:

On a test that has a normal distribution, a score of 82 falls three standard deviations above the mean, and a score of 64 falls one standard deviation above the mean. Determine the mean of this test.

Answers

Answer: mean = 55

Step-by-step explanation:

Distance between 64 and 82 = 18

Each standard deviation is worth 9 units.

So 64 - 9 = 55(mean)

Or use m= x-zq

Express the lengths a and b in the figure in terms of theta. If sin(x) = 1/3 and sec(y) = 5/4, where x and y lie between 0 and pi/2, evaluate sin(x + y) Find all values of x such that sin 2x = sin x and 0 le x le 2pi. (List the answers in increasing) If you have had difficulty with these problems, you may wish to consult the Review of Trigonometry.

Answers

In the given figure, the length b is opposite the angle theta, and the length a is adjacent to the angle theta, so we can use the trigonometric ratios to express a and b in terms of theta:

What does trigonometry mean in plain English?

Trigonometry is the branch of mathematics that deals with particular angles' functions and how to use those functions in calculations. There are six popular trigonometric functions for an angle. Sine (sin), cosine (cos), tangent (tan), cotangent (cot), secant (sec), and cosecant are their respective names and acronyms (csc).

a = bsec(theta)

b = acosec(theta)

To evaluate sin(x+y), we can use the identity sin(a+b) = sin(a)cos(b) + cos(a)sin(b)

sin(x+y) = sin(x)cos(y) + cos(x)sin(y)

We can use the given information to substitute the values of sin(x) and cos(y)

sin(x) = 1/3, cos(y) = sqrt(1 - (5/4)^2) = sqrt(9/16)

sin(x+y) = (1/3) * sqrt(9/16) + sqrt(9/16) * (1/3) = (3sqrt(9) + 9) / 48

To find all values of x such that sin 2x = sin x and 0 le x le 2pi, we can set sin 2x = sin x and solve for x.

sin 2x = sin x

2sinxcosx = sinx

cosx = 1/2

x = pi/3,5*pi/3

So the values of x that satisfy the equation are x = pi/3 and 5*pi/3

Note that these values are in radians, if you need in degree, x=60°, 300°

Learn more about trigonometry

https://brainly.com/question/24349828

#SPJ4

what is 2/5 of 12,500

Answers

Answer: it's 5000 :)

Step-by-step explanation:

Answer: 5000

Step-by-step explanation:


set of points is shown on the graph.

Scatter plot with a point at negative 3 comma 9, a point at 0 comma 5, a point at 1 comma 8, a point at 6 comma 7, and a point at 8 comma 3.

Which of the following equations is the best model for a line of fit for the data?

y equals 2 thirds times x plus 7
y equals negative 2 thirds times x plus 7
y equals 1 third times x plus 7
y equals negative 1 third times x plus 7

Answers

An equation which represents the best model for a line of fit for the data is: y equals negative 2 thirds times x plus 7. The correct option is A.

How to find a line of fit for the data?

A scatter plot should be used to determine a linear equation of the line of best fit (trend line) that models the data points described above.

In this scenario, the x-values would be plotted on the scatter plot's x-axis, while the y-values would be plotted on the scatter plot's y-axis.

Right-click on any data point on the scatter plot in Excel, select the format trend line, and then check the box to display an equation for the line of best fit (trend line) on the scatter plot.

From the scatter plot (see attachment) which models the relationship between data points in the table, a linear equation for the line of best fit is given by:

y = -0.33x + 7.

Rewriting the equation as an improper fraction, we have:

y = -2/3(x) + 7

Read more on scatter plots here:

brainly.com/question/28605735

#SPJ1

A newly-planted tree needs to be staked with three wires. Each wire is attached to the trunk 3ft. above the ground, and then anchored to the ground 2.5 ft. from the base of the tree. Estimate about how much wire is needed for 6 trees?

Answers

33ft wire is needed for 6 trees.

What is addition?

Addition is a way of combining things and counting them together as one large group. ... Addition in math is a process of combining two or more numbers.

here, we have,

Each wire is attached to the trunk 3ft. above the ground,

and then anchored to the ground 2.5 ft. from the base of the tree.

So, for each tree total wire = 3+2.5

                                             =5.5 ft.

So, for 6 trees = 5.5*6

                       =33ft

Hence, 33ft wire is needed for 6 trees.

To earn more on addition click:

brainly.com/question/29560851

#SPJ1

Two lines that make right angles at their intersection are?

Answers

Two lines that make right angles at their intersection are Perpendicular lines.

What is perpendicular in lines?Perpendicular lines are those that cross at a straight angle of 90 degrees.When two lines cross at a straight angle or 90 degree, perpendicular lines are created. Perpendicularity is the name given to this characteristic of lines. In-depth discussions of what a perpendicular is, its characteristics, how it differs from a parallel line, as well as several instances with solutions will all be covered in this article.A perpendicular is a straight line in mathematics that forms a right angle (90 degrees) with another line. In other words, two lines are perpendicular to one another if they connect at a right angle.

Learn more about Perpendicular lines refer to ;

https://brainly.com/question/28063031

#SPJ4

At a Mexican retaurant, you order a taco for $1. 85 and burrito dinner for $7. 35. Sale tax i 7. 5% and you leave a tip of 15%. What i your total bill including tip and tax?

Answers

So, your total bill including tip and tax is $11.37

First, calculate the subtotal of the food bill by adding the cost of the taco and burrito dinner:

$1.85 + $7.35 = $9.20

Next, calculate the sales tax by multiplying the subtotal by the tax rate (7.5%):

$9.20 x 0.075 = $0.69

Then add the sales tax to the subtotal to get the total before tip:

$9.20 + $0.69 = $9.89

Then calculate the tip by multiplying the total before tip by the tip rate (15%):

$9.89 x 0.15 = $1.48

Finally, add the tip to the total before tip to get the final total bill including tip and tax:

$9.89 + $1.48 = $11.37

So, your total bill including tip and tax is $11.37

To learn more about Percentages

Visit; brainly.com/question/13450942

#SPJ4

$1.85 + $7.35 = $9.20

$9.20 x 0.075 = $0.69

$9.20 + $0.69 = $9.89

$9.89 x 0.15 = $1.48

$9.89 + $1.48 = $11.37

So, your total bill including tip and tax is $11.37

A pair of shoes regularly cost $45. Today, they are marked down 25%. What is the sale price of the pair of shoes?​

Answers

Answer:

$33.75

Step-by-step explanation:

25% of 45 is 11.25 meaning you would get that much off as a discount making the shoes be $33.75

For what value of the variable i the value of the expreion – 3(2x 1) twenty greater than the value of the expreion 8x 5?

Answers

The value of the variable for which the value of the expression –3(2x+1) is 20 is greater than the value of the expression 8x+5 is -2.

According to the question, 20 greater than 8x +5 = 8x +5 +20 = 8x +25.

We want this value to be -3(2x +1),

So, solving this equation we get: 8x +25 = -3(2x +1)

=> 8x +25 = -6x -3 (eliminating the parentheses)

Further solving this equation we get,

=> 14x = -28

=> x= -2

Thus, The value of the variable for which the value of the expression –3(2x+1) is 20 is greater than the value of the expression 8x+5 is -2.

Complete question: Find the value of the variable for which the value of the expression –3(2x+1) is 20 greater than the value of the expression 8x+5.

To know more about variables visit: brainly.com/question/2466865

#SPJ4

The value of the variable for which the value of the expression –3(2x+1) is 20 is greater than the value of the expression 8x+5 is -2.

According to the question, 20 greater than 8x +5 = 8x +5 +20 = 8x +25.

We want this value to be -3(2x +1),

8x +25 = -3(2x +1)

8x +25 = -6x -3 (eliminating the parentheses)

14x = -28

x= -2

please help, i dont understand!

Answers

10y⁶ is the width of the rectangle and y²+3 is the length of the rectangle.

What is Area of Rectangle?

The area of Rectangle is length times of width.

Given that the area of rectangle is 70y⁸+30y⁶

The width of the rectangle is the greatest common factor of 70y⁸ and 30y⁶

70y⁸+30y⁶

10y⁶(y²+3)

10y⁶ is the width of the rectangle.

y²+3 is the length of the rectangle.

Hence, 10y⁶ is the width of the rectangle and y²+3 is the length of the rectangle.

To learn more on Rectangles click:

https://brainly.com/question/20693059

#SPJ1

Please help me understand

Answers

The perimeter of the horse corral is 600 feet.

What is Area of Rectangle?

The area of Rectangle is length times of width.

The area of any regular polygon is given by the formula: Area = (a x p)/2, where a is the length of the apothem and

p is the perimeter of the polygon.

Given that area of the horse corral is 3000 ft²

Length of the apothem is 10 ft

We need to find the perimeter.

3000=10p/2

6000=10p

Divide both sides by 10

600=perimeter

Hence, the perimeter of the horse corral is 600 feet.

To learn more on Rectangle click:

https://brainly.com/question/20693059

#SPJ1

Other Questions
which collaborative action would be best to rehydrate an alert client seen in the urgent care center with dehydration, a heart rate of 100 beats/minute, and blood pressure of 104/62 mm hg? The ratio of the number of boy in the cla who play football to thoe who play cricket i 3:5. What percentage of boy play cricket? (anwer quickly pleae) Find the molecular formula for a compound made up of 85.6 % carbon and 14.4%hydrogen by mass that has a molar mass of 70.15 g/mol. What is the surface area of this right rectangular prism with dimensions of 4 centimeters by 4 centimeters by 6 centimeters? the career coach in the video speaks about and demonstrates effective strategies for asking for a raise. which of the following is not one of these strategies? perception is the . group of answer choices process by which people take all the sensations they experience at any given moment and interpret them in some meaningful fashion action of physical stimuli on receptors leading to sensations interpretation of memory based on selective attention act of selective attention from sensory storage identify examples of how globalization has affected the field of anthropology. In Exercises 1-8, find the area of the shaded region. The radius of each circle is r. If two circles are shown, r is the radius of the smaller circle and R is the radius of the larger circle. 1. r= 6 cm 2. r= 8 cm 3. r = 16 cm 160 24001 4. r= 2 cm 5. r= 8 cm 6. R= 7 cm r= 4 cm Use the given values of n and p to find the minimum usual value and the maximum usual value 2. Round your answer to the nearest hundredth unless otherwise noted.n = 248, p = ?Question options:a) Minimum: 75.64; maximum: 48.36b) Minimum: 52.36; maximum: 71.64c) Minimum: 55.18; maximum: 68.82d) Minimum: 48.36; maximum: 75.64 what is the correct inequality What is the main idea of the Declaration of Independence by Thomas Jefferson?. what is the purpose of looking for movement of the meniscus? Suppose b, c R. Define T: P(R) R2 by Tp=(3p(4) + 5p'(6)+bp(1)p(2), x3 p(x) dx + c sin p(0) Show that T is linear if and only if b = c = 0. What are the various means by which you communicate with your family and friends? Are these appropriate ways to communicate with elected officials? Why or why not? which of the following summarizes the financial performance of an organization over a period of time? a. Balance sheetb. Liquidity ratioc. Cash flow statementd. Income statemente. Debt statement when the soviets launched _______________, america devoted even more resources to space and technology research. help please i dont understand this! Suppose the cost of a business property is $7,100,000 and a company depreciates it with the straight-line method. If V is the value of the property after x years and the line representing the value as a function of years passes through the points (90,1520000) and (100,900000), write the equation that gives the annual value of the property. a developed country has an established infrastructure, service-based economy, and is typically highly industrialized with a high per capita income. based on their descriptions above, which of the following countries are developed? g a cusp point (or a point where the curve changes direction abruptly instead of smoothly) can occur when: