Ratios and Proportions

Front

What is a ratio?

Back

A ratio is a comparison of two quantities by division, expressed as 'a:b' or 'a/b'.

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal, expressed as 'a/b = c/d'.

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the terms and then isolate the variable.

Front

If the ratio of red fish to blue fish is 3:5 and there are 20 blue fish, how many red fish are there?

Back

12 red fish.

Front

What is the cross-multiplication method?

Back

Cross-multiplication involves multiplying the numerator of one ratio by the denominator of the other ratio.

Front

If 2/3 = x/12, what is x?

Back

x = 8.

Front

What does it mean if two ratios are equivalent?

Back

It means that they represent the same relationship between quantities.

Front

If a recipe calls for a ratio of 2:3 of sugar to flour, how much sugar is needed for 9 cups of flour?

Back

6 cups of sugar.

Front

What is the formula for finding a missing term in a proportion?

Back

If a/b = c/x, then x = (b*c)/a.

Front

If k/4 = 5/20, what is k?

Back

k = 1.