In a school, there is a total of 1075 people.
40% are adults.
The rest are children.
The number of girls and boys is in the ratio of 1 : 4.
- What percentage of the people are girls?
- How many boys are there?
Adults |
Children |
Total |
2x5 |
3x5 |
5x5 |
|
Girls |
Boys |
|
|
1x3 |
4x3 |
|
10 u |
3 u |
12 u |
25 u |
(a)
40% =
40100 =
25 Adults : Children
2 : 5 - 2
2 : 3
Girls : Boys : Children
1 : 4 : 5
The number of children is the combined repeated identity.
Make the number of children the same using the LCM of 3 and 5.
LCM of 3 and 5 = 15
Percentage of the people that are girls
=
325 x 100%
= 12%
(b)
Total number of people = 25 u
25 u = 1075
1 u = 1075 ÷ 25 = 43
Number of boys
= 12 u
= 12 x 43
= 516
Answer(s): (a) 12%; (b) 516