Ratios and Proportions

Front

What is a ratio?

Back

A ratio is a comparison of two quantities, showing the relative size of one quantity to another.

Front

How do you write a ratio in simplest form?

Back

To write a ratio in simplest form, divide both terms of the ratio by their greatest common divisor (GCD).

Front

What is the ratio of 10 automobiles to 13 bikes in simplest form?

Back

10/13

Front

If 11/13 = n/39, what is the value of n?

Back

n = 33.

Front

What is the ratio of red apples to green apples if there are 4 red apples and 3 green apples?

Back

The ratio is 4 red apples to 3 green apples.

Front

What is a proportion?

Back

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

Front

How can you determine if two ratios form a proportion?

Back

Two ratios form a proportion if their cross products are equal.

Front

What is the cross product of the ratios 2/3 and 4/6?

Back

The cross product is 2 * 6 = 12 and 3 * 4 = 12, so they are equal, confirming the ratios form a proportion.

Front

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

Back

If a/b = c/d, then ad = bc, where a, b, c, and d are the terms of the proportion.

Front

How do you convert a ratio to a percentage?

Back

To convert a ratio to a percentage, divide the first term by the second term and multiply by 100.