Ratios: Part-Part and Part-Whole

Front

What is a ratio?

Back

A ratio is a comparison of two quantities that shows the relative size of one quantity to another, often expressed as 'a:b'.

Front

What does 'part-part ratio' mean?

Back

A part-part ratio compares two parts of a whole, such as the ratio of boys to girls in a class.

Front

What does 'part-whole ratio' mean?

Back

A part-whole ratio compares a part of a quantity to the entire quantity, such as the ratio of girls to the total number of students.

Front

How do you solve for a missing value in a ratio?

Back

To solve for a missing value in a ratio, set up a proportion and cross-multiply to find the unknown.

Front

If the ratio of boys to girls is 3:4, how many boys are there if there are 28 girls?

Back

There are 21 boys. (3/4 = x/28; x = 21)

Front

What is the ratio of 12 to 16 in simplest form?

Back

The simplest form of the ratio 12:16 is 3:4.

Front

How do you convert a ratio to a fraction?

Back

To convert a ratio to a fraction, write the first quantity as the numerator and the second quantity as the denominator.

Front

If a recipe calls for a ratio of 2:3 of sugar to flour, how much sugar is needed for 15 cups of flour?

Back

You need 10 cups of sugar. (2/3 = x/15; x = 10)

Front

What is the total number of parts in a ratio of 5:7?

Back

The total number of parts is 12 (5 + 7).

Front

If a mixture has a ratio of 1:4 of chemical A to chemical B, how much chemical B is needed for 10 liters of the mixture?

Back

You need 40 liters of chemical B. (1 part A + 4 parts B = 5 parts total; 10 liters / 5 parts = 2 liters per part; 4 parts B = 8 liters.)