In a school, there is a total of 180 people.
30% are adults.
The rest are children.
The number of girls and boys is in the ratio of 3 : 4.
- What percentage of the people are girls?
- How many boys are there?
Adults |
Children |
Total |
3 u |
7 u |
10 u |
|
Girls |
Boys |
|
3 u |
3 u |
4 u |
10 u |
(a)
30% =
30100 =
310 The number of children is the combined repeated identity.
Adults : Children
3 : 10 - 3
3 : 7
Percentage of the people that are girls
=
310 x 100%
= 30%
(b)
Total number of people = 10 u
10 u = 180
1 u = 180 ÷ 10 = 18
Number of boys
= 4 u
= 4 x 18
= 72
Answer(s): (a) 30%; (b) 72