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 terms and then solve for the unknown variable.

Front

If 4 pages take 18 minutes to read, how do you find the time for 30 pages?

Back

Set up the proportion: 4 pages/18 minutes = 30 pages/x minutes, then cross-multiply and solve for x.

Front

What is the unit rate?

Back

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

Front

How do you find the cost per apple if 50 apples cost $25.00?

Back

Divide the total cost by the number of apples: $25.00 / 50 apples = $0.50 per apple.

Front

If Nathan packs 39 boxes in 3 hours, how do you find the number of boxes he can pack in 8 hours?

Back

First find the rate: 39 boxes / 3 hours = 13 boxes/hour. Then multiply by 8 hours: 13 boxes/hour * 8 hours = 104 boxes.

Front

What does it mean to solve for x in an equation?

Back

To solve for x means to find the value of x that makes the equation true.

Front

If 50 apples cost $25.00, how much do 75 apples cost?

Back

Set up the proportion: 50 apples/$25.00 = 75 apples/x, then cross-multiply and solve for x to find $37.50.

Front

What is cross-multiplication?

Back

Cross-multiplication is a method used to solve proportions by multiplying the numerator of one ratio by the denominator of the other ratio.

Front

How do you find the total time taken if you know the time per unit?

Back

Multiply the time per unit by the total number of units.