In a school, the ratio of adults to the number of children is 1 : 6.
The ratio of the number of girls to the number of boys is 7 : 3.
There are 84 more girls than boys.
How many people are there in the school?
Adults |
Children |
1 x 5 |
6 x 5 |
|
Girls |
Boys |
|
7 x 3 |
3 x 3 |
5 u |
21 u |
9 u |
The number of children is the combined repeated identity.
Make the number of children the same using the LCM of 6 and 10.
LCM of 6 and 10 = 30
Number of more girls than boys
= 21 u - 9 u
= 12 u
12 u = 84
1 u = 84 ÷ 12 = 7
Number of people
= 5 u + 21 u + 9 u
= 35 u
= 35 x 7
= 245
Answer(s): 245