Section: Math Section 2

28) In a certain set of numbers, the ratio of integers to nonintegers is 1:4. What percent of the numbers in the set are integers?

1. 20%
2. 25%
3. 40%
4. 75%
5. 80%

When you know that the given parts add up to the whole, then you can turn a part-to-part ratio into two part-to- whole ratios — put each term of the ratio over the sum of the terms. In this case, since all the numbers in the set must be either integers or nonintegers, the parts do add up to the whole. The sum of the terms in the ratio 1:4 is 5, so the two part-to-whole ratios are 1:5 and 4:5.