Proportion Story Problems

Front

What is a proportion?

Back

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

Front

How do you set up a proportion to solve a problem?

Back

To set up a proportion, you can use the formula a/b = c/d, where a and b are one ratio, and c and d are another ratio.

Front

What is the cross-multiplication method?

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

If a car travels 420 miles in 8 hours, how do you find the rate of travel?

Back

To find the rate, divide the distance by the time: Rate = Distance / Time = 420 miles / 8 hours = 52.5 miles per hour.

Front

How do you find the distance traveled if you know the rate and time?

Back

Distance = Rate x Time. If the rate is 52.5 miles per hour and time is 12 hours, then Distance = 52.5 x 12 = 630 miles.

Front

What is the formula to find time when distance and rate are known?

Back

Time = Distance / Rate.

Front

If a grading machine can grade 48 tests in 1 minute, how do you find the time to grade 300 tests?

Back

Set up a proportion: 48 tests / 1 minute = 300 tests / x minutes. Cross-multiply and solve for x.

Front

What is the unit rate?

Back

The unit rate is a comparison of any quantity to one unit of another quantity.

Front

How do you find the number of items needed based on a ratio?

Back

Use the ratio to set up a proportion and solve for the unknown quantity.

Front

If Pat needs 14 sticks of pepperoni for 28 pizzas, how many sticks are needed for 36 pizzas?

Back

Set up a proportion: 14 sticks / 28 pizzas = x sticks / 36 pizzas. Solve for x to find 18 sticks.