In a school, the ratio of children to the number of adults is 7 : 8.
The ratio of the number of women to the number of men is 7 : 2.
There are 80 less men than women.
How many people are there in the school?
| Children |
Adults |
| 7 x 9 |
8 x 9 |
| |
Women |
Men |
| |
7 x 8 |
2 x 8 |
| 63 u |
56 u |
16 u |
The number of adults is the combined repeated identity.
Make the number of adults the same using the LCM of 8 and 9.
LCM of 8 and 9 = 72
Number of less men than women
= 56 u - 16 u
= 40 u
40 u = 80
1 u = 80 ÷ 40 = 2
Number of people
= 63 u + 56 u + 16 u
= 135 u
= 135 x 2
= 270
Answer(s): 270
