# Ratios and Proportions

Words of “Wiz-dom”—Ratio problems are just fractions and percents in disguise. Think about them as parts of a whole. Just like means three of four parts with four parts making up the whole, a ratio of 3:1 means the same thing. It means three parts to one part with four parts as the whole.

 The test writer wants to know if you realize the key to ratio problems is the sum of the parts.

At Wiz-dom High, the teachers only drive Fords, Chevrolets, and Plymouths. In the teachers’ parking lot there are 60 Fords, 40 Chevrolets and 20 Plymouths.

• What fraction of the cars are Chevrolets?
• What percent of the cars are Plymouths?
• What is the ratio of Fords to Plymouths?
• What is the ratio of Chevrolets to Fords and Plymouths?
• What is the ratio of Fords to all the cars in the parking lot?

Answers to the questions on ratios and proportions

## Sample Questions

 1 The ratio of left-handed to right-handed students is 1:19 at Much Wizer High School. If there are 1800 students at the school, how many are left-handed? A. 18 B. 36 C. 90 D. 1700 E. 1710

 2 The ratio of juniors to seniors is 21 to 19 at Draw Bridge High School. How many students could be juniors and seniors combined? A. 1250 B. 1420 C. 1580 D. 1600 E. 1650

 3 The ratio of seniors to juniors to sophomores who bought yearbooks at Magic Dragon High is 11:9:5. What percent of the yearbook buyers were seniors?A. 11 B. 20 C. 40 D. 44 E. 72

 4 A model castle company sells models that are on a scale of 24:1. If an original castle tower was 84 feet tall, how many inches tall will the model tower be?A. 3 B. 3.5 C. 36 D. 42 E. 84