In a school, the ratio of children to the number of adults is 7 : 10.
The ratio of the number of men to the number of women is 8 : 7.
There are 42 more men than women.
How many people are there in the school?
Children |
Adults |
7 x 3 |
10 x 3 |
|
Men |
Women |
|
8 x 2 |
7 x 2 |
21 u |
16 u |
14 u |
The number of adults is the combined repeated identity.
Make the number of adults the same using the LCM of 10 and 15.
LCM of 10 and 15 = 30
Number of more men than women
= 16 u - 14 u
= 2 u
2 u = 42
1 u = 42 ÷ 2 = 21
Number of people
= 21 u + 16 u + 14 u
= 51 u
= 51 x 21
= 1071
Answer(s): 1071