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 set the products equal to each other.

Front

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

Back

If a/b = c/d, then ad = bc. You can find the missing value by rearranging this equation.

Front

If 3 apples cost $1.50, how much do 12 apples cost?

Back

$6.00 (Set up the proportion: 3/1.50 = 12/x, cross-multiply to find x).

Front

What is a ratio?

Back

A ratio is a comparison of two quantities by division.

Front

If the ratio of boys to girls is 3:2 and there are 15 boys, how many girls are there?

Back

10 girls (Set up the proportion: 3/2 = 15/x, cross-multiply to find x).

Front

What is the relationship between ratios and proportions?

Back

Ratios compare two quantities, while proportions state that two ratios are equal.

Front

If a recipe requires 2 cups of flour for every 3 cups of sugar, how much flour is needed for 9 cups of sugar?

Back

6 cups of flour (Set up the proportion: 2/3 = x/9, cross-multiply to find x).

Front

How can you use proportions to solve real-world problems?

Back

Proportions can be used to scale quantities, compare rates, and solve problems involving ratios.

Front

If 5 pounds of potatoes cost $3, how much do 15 pounds cost?

Back

$9 (Set up the proportion: 5/3 = 15/x, cross-multiply to find x).