In a school, there is a total of 240 people.
30% are adults.
The rest are children.
The number of girls and boys is in the ratio of 2 : 5.
- 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 |
2 u |
5 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
=
210 x 100%
= 20%
(b)
Total number of people = 10 u
10 u = 240
1 u = 240 ÷ 10 = 24
Number of boys
= 5 u
= 5 x 24
= 120
Answer(s): (a) 20%; (b) 120