Solving Proportions

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the two ratios and then solve for the unknown variable.

Front

What does it mean for two ratios to be proportional?

Back

Two ratios are proportional if they can be expressed as equivalent fractions.

Front

If Mary ran 2 miles in 23 minutes, what is her pace in minutes per mile?

Back

Her pace is 11.5 minutes per mile (23 minutes / 2 miles).

Front

How long will it take Mary to run 10 miles at the same pace?

Back

It will take her 115 minutes (10 miles * 11.5 minutes per mile).

Front

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

Back

If a/b = c/d, then ad = bc, where a, b, c, and d are the values in the proportion.

Front

Solve the proportion: 3/4 = x/16. What is x?

Back

x = 12.

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 5/8 = x/32, how do you find x?

Back

Cross-multiply: 5 * 32 = 8 * x, so x = 20.

Front

What is a unit rate?

Back

A unit rate is a comparison of two different quantities when they are combined together, expressed as a quantity per one unit.