    ### Ratios

A ratio is a comparison between two or more quantities. The colon is used to show ratios. 6 : 8 and 8 : 20 are ratios.

#### Example 1.   Share £60 in the ratio 2 : 3

(a)  Add the separate parts of the ratio to find the total number of parts
2 + 3 = 5
(b)   Divide 60 by 5 to find the value for each part: 12
(c)   Multiply each term in the ratio by 12:
2 x 12 = 24, 3 x 12 = 36

So £60 shared in the ratio 2 : 3 is £24 and £36

#### Example 2.   The cost of going to the cinema is divided between two families in the ratio of 3 : 5 the smaller share is £60. How much is the total cost of the cinema?

(a)  Add the separate parts of the ratio to find the total number of parts
3 + 5 = 8
(b)   3/8 of the cost was £60, so 1/8 is £20
(c)   The total cost is 8 x £20 = £160

So the total cost is £160

#### Example 3.   The ratio of female employees to male employees is 3 : 7. If there are 84 female employees, how many male employees are there?

(a)  Add the separate parts of the ratio to find the total number of parts
3 + 7 = 10
(b)   So 3/10 are female employees is 84, so 1/10 is 28
(c)   The number of male employees: 7 x 28 = 196

So the number of male employees are 196 to:  