In a school, the ratio of adults to the number of children is 6 : 7.
The ratio of the number of girls to the number of boys is 5 : 2.
There are 39 more girls than boys.
How many people are there in the school?
Adults |
Children |
6 x 1 |
7 x 1 |
|
Girls |
Boys |
|
5 x 1 |
2 x 1 |
6 u |
5 u |
2 u |
The number of children is the combined repeated identity.
Make the number of children the same using the LCM of 7 and 7.
LCM of 7 and 7 = 7
Number of more girls than boys
= 5 u - 2 u
= 3 u
3 u = 39
1 u = 39 ÷ 3 = 13
Number of people
= 6 u + 5 u + 2 u
= 13 u
= 13 x 13
= 169
Answer(s): 169