SAT Math : Whole and Part

Study concepts, example questions & explanations for SAT Math

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Example Questions

Example Question #33 : Percentage

An artist's new album sold  copies on its release date. If the U.S. makes up  of these sales, how many copies were sold on that day in the U.S.?

Possible Answers:

Correct answer:

Explanation:

Let's set up a proportion to solve this problem, where  represents the number of copies sold in the U.S. Remember that we can express  as a fraction.

Now, we can solve for the unknown by cross-multiplying. 

Example Question #11 : Whole And Part

Jane called one thousand times to tell you she's sorry. If you saw she was calling and let your phone go to voicemail  of the time, how many voicemails would you have received if she left one each time?

Possible Answers:

None of the given answers

Correct answer:

Explanation:

To solve this problem, we can set up a proportion. Remember we can express percentages as fractions. Let  represent the number of voicemails. 

Now, we can cross-multiply and solve for the unknown.

Example Question #1081 : Sat Mathematics

 is what percentage of 

Possible Answers:

Cannot be determined

Correct answer:

Explanation:

To solve this we need to set up a proportion.

Now we cross multiply

Divide by 180.

Example Question #1082 : Sat Mathematics

Sat_math_131_01

David's trip expenses are pictured in the above pie chart (numbers = % of his total expenses). If he spent $75 on taxis, how much did he spend on hotel and souvenirs combined?

Possible Answers:

$225

$175

$200

$40

$250

Correct answer:

$200

Explanation:

David spent $75 on taxis, which were 15% of his total expenses on the trip. He therefore spent 75(100/15) = $500 on the trip altogether. The hotel and souvenirs make up 35% + 5% = 40% of his total expenses. 40% of 500 is $200.

Example Question #2 : How To Find The Whole From The Part With Percentage

30% of what number is 20?

Solve to the nearest hundredth.

Possible Answers:

None of the other answers

150%

66.67

0.67

1.5

Correct answer:

66.67

Explanation:

This is a very basic form percentage question. This can be rewritten:

0.3 * x = 20

(Remember, the word "of" in a word problem indicates multiplication, while the word "is" indicates an equals sign).

Solve for x: x = 20 / 0.3 = 66.67

Example Question #3 : How To Find The Whole From The Part With Percentage

A toy is on sale for 43% off. Its sale price is $21.37. What is the full price?

Possible Answers:

\$ 49.70

\$ 37.49

\$ 33.55

None of the available answers

\$ 30.56

Correct answer:

\$ 37.49

Explanation:

An algebraic expression for this item is:

(1-0.43)x=21.37

x=\frac{21.37}{1-0.43}=\$ 37.49

Example Question #4 : How To Find The Whole From The Part With Percentage

Twenty-six students planned to contribute an equal amount to purchase a gift for their teacher. After 18 students had paid, they had collected $76.50. What is the total price of the gift?

Possible Answers:

Correct answer:

Explanation:

If $76.50 had been collected after 18 students had paid, we can determine how much each student contributed:    

$76.50/18 = $4.25 per student

Now we can multiply this by the total number of students (26) to get the full price of the gift:

26 x $4.25 = $110.50

Example Question #5 : How To Find The Whole From The Part With Percentage

If  of  is , then what is  of ?

Possible Answers:

200

100

10

20

50

Correct answer:

50

Explanation:

The first part of the problem tells us that x% of 20 is 50. We can model x% as x/100 or 0.01x. To find x% of 20, we can multiply 0.01x and 20. In other words, we can write the following equation:

(0.01x)(20) = 50

Divide both sides by 20.

0.01x = 2.5

Divide both sides by 0.01.

x = 250.

The question then asks us to find 20% of x. We can represent 20% as 0.2, and we know that x is 250. Therefore,

20% of 250 = 0.2(250) = 50.

The answer is 50.

Example Question #6 : How To Find The Whole From The Part With Percentage

If  of a number is , what is  of the number?

Possible Answers:

Correct answer:

Explanation:

Let x be the number in question.

Then 2/3 * x = 18.

x = 18 * 3/2 = 27

Now find 1/9 of 27:

1/9 * 27 = 3

Example Question #42 : Percentage

17 is 85% of what number?

Possible Answers:

Correct answer:

Explanation:

In this case, 17 is part of a whole x. We are also given that 17 is 85% of x. 

With this in mind, we can set up the following proportion.

To solve for x, cross multiply.

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