In a school, the ratio of adults to the number of children is 5 : 1.
The ratio of the number of girls to the number of boys is 3 : 1.
There are 84 more girls than boys.
How many people are there in the school?
Adults |
Children |
5 x 4 |
1 x 4 |
|
Girls |
Boys |
|
3 x 1 |
1 x 1 |
20 u |
3 u |
1 u |
The number of children is the combined repeated identity.
Make the number of children the same using the LCM of 1 and 4.
LCM of 1 and 4 = 4
Number of more girls than boys
= 3 u - 1 u
= 2 u
2 u = 84
1 u = 84 ÷ 2 = 42
Number of people
= 20 u + 3 u + 1 u
= 24 u
= 24 x 42
= 1008
Answer(s): 1008