In a school, the ratio of children to the number of adults is 5 : 3.
The ratio of the number of men to the number of women is 4 : 1.
There are 18 more men than women.
How many people are there in the school?
Children |
Adults |
5 x 5 |
3 x 5 |
|
Men |
Women |
|
4 x 3 |
1 x 3 |
25 u |
12 u |
3 u |
The number of adults is the combined repeated identity.
Make the number of adults the same using the LCM of 3 and 5.
LCM of 3 and 5 = 15
Number of more men than women
= 12 u - 3 u
= 9 u
9 u = 18
1 u = 18 ÷ 9 = 2
Number of people
= 25 u + 12 u + 3 u
= 40 u
= 40 x 2
= 80
Answer(s): 80