In a school, the ratio of adults to the number of children is 9 : 4.
The ratio of the number of girls to the number of boys is 4 : 3.
There are 100 more girls than boys.
How many people are there in the school?
Adults |
Children |
9 x 7 |
4 x 7 |
|
Girls |
Boys |
|
4 x 4 |
3 x 4 |
63 u |
16 u |
12 u |
The number of children is the combined repeated identity.
Make the number of children the same using the LCM of 4 and 7.
LCM of 4 and 7 = 28
Number of more girls than boys
= 16 u - 12 u
= 4 u
4 u = 100
1 u = 100 ÷ 4 = 25
Number of people
= 63 u + 16 u + 12 u
= 91 u
= 91 x 25
= 2275
Answer(s): 2275