In a school, the ratio of children to the number of adults is 2 : 1.
The ratio of the number of women to the number of men is 5 : 2.
There are 15 less men than women.
How many people are there in the school?
Children |
Adults |
2 x 7 |
1 x 7 |
|
Women |
Men |
|
5 x 1 |
2 x 1 |
14 u |
5 u |
2 u |
The number of adults is the combined repeated identity.
Make the number of adults the same using the LCM of 1 and 7.
LCM of 1 and 7 = 7
Number of less men than women
= 5 u - 2 u
= 3 u
3 u = 15
1 u = 15 ÷ 3 = 5
Number of people
= 14 u + 5 u + 2 u
= 21 u
= 21 x 5
= 105
Answer(s): 105