Ratio and Proportions

Front

What is a ratio?

Back

A ratio is a comparison of two quantities by division, expressed as 'a:b' or 'a/b'.

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal, expressed as 'a:b = c:d'.

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the terms and set the products equal to each other.

Front

What does it mean for two ratios to be equivalent?

Back

Two ratios are equivalent if they represent the same relationship between quantities, e.g., 1:2 is equivalent to 2:4.

Front

If a class has 30 students and 18 are boys, how many are girls?

Back

12 girls (30 - 18 = 12).

Front

What is the ratio of boys to girls in the class?

Back

The ratio of boys to girls is 3:2.

Front

What is the value of x in the proportion 3/4 = x/16?

Back

x = 12 (cross-multiply: 3*16 = 4*x).

Front

If 5:10 is simplified, what is the simplest form?

Back

The simplest form of 5:10 is 1:2.

Front

What is the cross-multiplication method?

Back

Cross-multiplication involves multiplying the numerator of one ratio by the denominator of the other ratio.

Front

Which of the following is NOT equivalent to 3:5? 15:25, 9:15, 21:28, 30:50

Back

21:28 is NOT equivalent to 3:5.