McGraw-Hill Education GRE 2019

Percentages

Part Versus Whole

A percent is another way to express a part-to-whole relationship. Percent literally

means “per one hundred” and is used to determine the piece that a quantity

represents when the whole is 100. For example, if Bob has 200 pies, and 75% of the

pies are blueberry, then the number of blueberry pies is

75% × 200 = 10075 × 200 = 0.75 × 200 =^34 × 200 = 150

Note from the preceding example that to convert from a percent to a

decimal, you should drop the percent and move the decimal two places

to the left. For example:

40% = 0.40 = 104 =^25

The formula to calculate percent is

part

whole =

p

100 , where p = percent

62 is what percent of 1,000?

SOLUTION: Use the percent formula: 62 is the part and 100 is the whole, so:

62

1,000 =

p

100

p = 1,000^62 × 100 = 6.2

Percent questions can be phrased in a few ways. Let’s look at a few examples and

how they fit into the preceding formula.

15 is what percent of 50?

SOLUTION: The part is 15 and the whole is 50. The solution is thus:

1550 = 100 p

1550 × 100 = p

p = 30

What percent of 200 is 350?

228 PART 4 ■ MATH REVIEW

03-GRE-Test-2018_173-312.indd 228 12/05/17 11:52 am