In a school, the ratio of children to the number of adults is 1 : 9.
The ratio of the number of women to the number of men is 2 : 1.
There are 90 less men than women.
How many people are there in the school?
Children |
Adults |
1 x 1 |
9 x 1 |
|
Women |
Men |
|
2 x 3 |
1 x 3 |
1 u |
6 u |
3 u |
The number of adults is the combined repeated identity.
Make the number of adults the same using the LCM of 9 and 3.
LCM of 9 and 3 = 9
Number of less men than women
= 6 u - 3 u
= 3 u
3 u = 90
1 u = 90 ÷ 3 = 30
Number of people
= 1 u + 6 u + 3 u
= 10 u
= 10 x 30
= 300
Answer(s): 300