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

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

Back

x = 16

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

If a car travels 150 miles in 3 hours, what is the speed in miles per hour?

Back

Speed = Distance/Time = 150 miles / 3 hours = 50 miles per hour.

Front

What is the scale in a scale drawing?

Back

The scale in a scale drawing is the ratio of the length in the drawing to the actual length.

Front

If a recipe calls for 2 cups of flour for 3 servings, how much flour is needed for 9 servings?

Back

6 cups of flour.

Front

What is the formula for finding the time taken if distance and speed are known?

Back

Time = Distance / Speed.

Front

If 5 apples cost $2, how much do 15 apples cost?

Back

$6.

Front

What is the relationship between ratios and proportions?

Back

Ratios are comparisons of two quantities, while proportions show that two ratios are equal.