Whole and Part - ACT Math
Card 0 of 17
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The preceding graph depicts students' favorite colors. If there are 30 students in the class, how many prefer blue?
The preceding graph depicts students' favorite colors. If there are 30 students in the class, how many prefer blue?
20% of the students prefer blue. We can calculate the number of students that prefer blue by multiplying the percentage by the total number of students.
20% of the students prefer blue. We can calculate the number of students that prefer blue by multiplying the percentage by the total number of students.
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The Smith family consumed 35 pounds of table salt last year. As part of a healthier diet, they would like to cut their table salt consumption by 40% this year. In order to reach this goal, what is the maximum amount of salt, in pounds, that the Smith family can consume this year?
The Smith family consumed 35 pounds of table salt last year. As part of a healthier diet, they would like to cut their table salt consumption by 40% this year. In order to reach this goal, what is the maximum amount of salt, in pounds, that the Smith family can consume this year?
We need to first find 40 percent of the amount of table salt that the Smith family consumed in the previous year. In order to calculate this, we need to convert 40 percent into a decimal by moving the decimal place two spaces to the left and multiplying it by last year's salt consumption.
Now, we need to subtract this amount from last year's salt consumption in order to calculate this years reduced consumption for the Smith family.
We need to first find 40 percent of the amount of table salt that the Smith family consumed in the previous year. In order to calculate this, we need to convert 40 percent into a decimal by moving the decimal place two spaces to the left and multiplying it by last year's salt consumption.
Now, we need to subtract this amount from last year's salt consumption in order to calculate this years reduced consumption for the Smith family.
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If n% of 400 is 260, then what is 20% of n?
If n% of 400 is 260, then what is 20% of n?
n% of 400 is 260
A number as a percentage of a second number is equal to the first number divided by the second number, times 100%.
260 / 400 * 100% = .65 * 100% = 65%. n = 65.
20% of n?
20% of 65 is equal to 65 * 20 / 100 = 65 / 5 = 13.
n% of 400 is 260
A number as a percentage of a second number is equal to the first number divided by the second number, times 100%.
260 / 400 * 100% = .65 * 100% = 65%. n = 65.
20% of n?
20% of 65 is equal to 65 * 20 / 100 = 65 / 5 = 13.
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Auditions are being held for the annual school musical. There are 18 roles available in the show. If 75 students try out, what percentage of the students will get a role in the musical?
Auditions are being held for the annual school musical. There are 18 roles available in the show. If 75 students try out, what percentage of the students will get a role in the musical?
Percentage is #roles / # students = 18 / 75 = 0.24 = 24%
Percentage is #roles / # students = 18 / 75 = 0.24 = 24%
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You are making cookies and mixing the dry ingredients: flour, white sugar and brown sugar. If the recipe calls for 3 1/4 cups of flour, 1/2 cup of white sugar and 3/4 cup of brown sugar, what percentage of the recipe is white sugar?
You are making cookies and mixing the dry ingredients: flour, white sugar and brown sugar. If the recipe calls for 3 1/4 cups of flour, 1/2 cup of white sugar and 3/4 cup of brown sugar, what percentage of the recipe is white sugar?
Total ingredients = 3 1/4 cups + 1/2 cup + 3/4 cup = 4 1/2 cups
White sugar percentage = white sugar / total = (1/2)/(9/2) = .111 = 11.1%
Total ingredients = 3 1/4 cups + 1/2 cup + 3/4 cup = 4 1/2 cups
White sugar percentage = white sugar / total = (1/2)/(9/2) = .111 = 11.1%
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Jamie bought shoes for 30% off the regular price of $37.99, rounded to the nearest cent. If she wanted to use exact change to pay, how much would she need in coins?
Jamie bought shoes for 30% off the regular price of $37.99, rounded to the nearest cent. If she wanted to use exact change to pay, how much would she need in coins?
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A class has 25 students. If 60% of them are boys, how many students are girls?
A class has 25 students. If 60% of them are boys, how many students are girls?
If 60% of the students are boys, 40% are girls 
. Multiply 25 by 40% 
. Therefore, 10 students are girls.
If 60% of the students are boys, 40% are girls
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is what part of 
?
Round your answer to the nearest percentage.
Round your answer to the nearest percentage.
To find how much percent 
is of 
, simply divide 
by 
and multiply that answer by 100.
Thus,
To find how much percent
Thus,
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95 is 20% of what number?
95 is 20% of what number?
multiply the part times 100 then divide by the percent.
(95 x 100) / 20 = 475
multiply the part times 100 then divide by the percent.
(95 x 100) / 20 = 475
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The average cow produces 8 gallons of milk per day. Scientists have found a vitamin supplement that can safely increase a cow’s milk production by 20%. If a dairy farm consisting of 100 cows uses the supplement, how many gallons of milk will the dairy farm now produce? (Assume each cow produces the average amount of milk per day).
The average cow produces 8 gallons of milk per day. Scientists have found a vitamin supplement that can safely increase a cow’s milk production by 20%. If a dairy farm consisting of 100 cows uses the supplement, how many gallons of milk will the dairy farm now produce? (Assume each cow produces the average amount of milk per day).
First, determine the amount of milk cows will produce with the supplement: 8 + (.2 x 8)= 9.6 gallons per day. Next, determine the amount of milk 100 cows will produce when receiving the supplement: 100 x 9.6 = 960 gallons.
First, determine the amount of milk cows will produce with the supplement: 8 + (.2 x 8)= 9.6 gallons per day. Next, determine the amount of milk 100 cows will produce when receiving the supplement: 100 x 9.6 = 960 gallons.
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A bowl contains 
marbles that are either red or green. The probability of selecting a red marble at random from the bowl is 
Which of the following expressions represents the total number of red marbles in the bowl?
A bowl contains
Which of the following expressions represents the total number of red marbles in the bowl?
It’s best to start with a fraction that is a part over 100. For this problem, we are looking for a fraction that shows 
. If you go through the choices available, 
. Therefore, if you plug in any value for “X” in this fraction, you will know the total number of marbles in the bowl. Here is an example:
If there are 4 marbles in the bowl, you’d expect 1 to be red. If we use this equation, we get
It’s best to start with a fraction that is a part over 100. For this problem, we are looking for a fraction that shows
If there are 4 marbles in the bowl, you’d expect 1 to be red. If we use this equation, we get
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Florida Clementines Corp sells only the best clementines. The inspector rejected 50% of January’s harvest. Unfortunately, 20% of the inspected clementines fell off the delivery truck. If the truck delivers 200 clementines, how many were harvested in January?
Florida Clementines Corp sells only the best clementines. The inspector rejected 50% of January’s harvest. Unfortunately, 20% of the inspected clementines fell off the delivery truck. If the truck delivers 200 clementines, how many were harvested in January?
We first obtain how many clementines were loaded on the delivery truck from 200 delivered clementines. Then we obtain how many clementines were inspected. 200 = (1-0.2)x gives us 250 loaded onto the delivery truck. 250 = (1-0.5)x gives us 500 harvested clementines.
We first obtain how many clementines were loaded on the delivery truck from 200 delivered clementines. Then we obtain how many clementines were inspected. 200 = (1-0.2)x gives us 250 loaded onto the delivery truck. 250 = (1-0.5)x gives us 500 harvested clementines.
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Ed eats 3 cookies every day. If he increases the total amount of cookies he has to begin with by 50%, it would take 21 days to finish all of his cookies. How many cookies does he have to begin with?
Ed eats 3 cookies every day. If he increases the total amount of cookies he has to begin with by 50%, it would take 21 days to finish all of his cookies. How many cookies does he have to begin with?
We let T be the total amount of cookies and D be the number of days it takes to eat all of the cookies before increasing by 50%, and A be the number of days after increasing by 50%. With the information given, we can write the expressions, T=3D and 1.5T=3A. For the second equation, we know A=21. We plug in and get T=42.
We let T be the total amount of cookies and D be the number of days it takes to eat all of the cookies before increasing by 50%, and A be the number of days after increasing by 50%. With the information given, we can write the expressions, T=3D and 1.5T=3A. For the second equation, we know A=21. We plug in and get T=42.
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Gwen has a collection of 1,000 books. The average thickness of each book is 1.25” thick. She wants to buy enough bookshelves that all of her books will fit on it.
What is the shortest length of bookshelf she should buy, in whole feet, to fit all her books?
Gwen has a collection of 1,000 books. The average thickness of each book is 1.25” thick. She wants to buy enough bookshelves that all of her books will fit on it.
What is the shortest length of bookshelf she should buy, in whole feet, to fit all her books?
Length of books = 1,000 books x 1.25” per book = 1,250”
Translate to feet
1” = 12’
1250” / 12 = 104.16 feet
Round up to 105 feet to be able to fit all the books.
Length of books = 1,000 books x 1.25” per book = 1,250”
Translate to feet
1” = 12’
1250” / 12 = 104.16 feet
Round up to 105 feet to be able to fit all the books.
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There are 8 blue balls in a bag. 40% of all the balls in the bag are blue. How many total balls are in the bag?
There are 8 blue balls in a bag. 40% of all the balls in the bag are blue. How many total balls are in the bag?
You evaluate 8/0.4 = 20.
You evaluate 8/0.4 = 20.
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If 
of a number is 
, what is 
of the number?
If
Since 
of the number is 
, the number is 
which equals 
. Then calculate 
of 
:
.
Since
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Nathan spends 
of his total homework time on Math. He spends one hour on Biology homework, which is twice the amount of time that he spends on Math. What is the total amount of time, in minutes, that Nathan spends on homework?
Nathan spends
If 
minutes of Biology (
) is twice as much time as that which is spent on Math (
), then Math must equal 30 minutes.
, so 
.
minutes is equivalent to 
of the total time (
): 
Solve for 
by dividing both sides of the equation by 
.
If
Solve for
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