In a school, there is a total of 400 people.
10% are adults.
The rest are children.
The number of girls and boys is in the ratio of 1 : 8.
- What percentage of the people are girls?
- How many boys are there?
Adults |
Children |
Total |
1 u |
9 u |
10 u |
|
Girls |
Boys |
|
1 u |
1 u |
8 u |
10 u |
(a)
10% =
10100 =
110 The number of children is the combined repeated identity.
Adults : Children
1 : 10 - 1
1 : 9
Percentage of the people that are girls
=
110 x 100%
= 10%
(b)
Total number of people = 10 u
10 u = 400
1 u = 400 ÷ 10 = 40
Number of boys
= 8 u
= 8 x 40
= 320
Answer(s): (a) 10%; (b) 320