In a school, the ratio of adults to the number of children is 3 : 4.
The ratio of the number of girls to the number of boys is 4 : 1.
There are 60 less boys than girls.
How many people are there in the school?
Adults |
Children |
3 x 5 |
4 x 5 |
|
Girls |
Boys |
|
4 x 4 |
1 x 4 |
15 u |
16 u |
4 u |
The number of children is the combined repeated identity.
Make the number of children the same using the LCM of 4 and 5.
LCM of 4 and 5 = 20
Number of less boys than girls
= 16 u - 4 u
= 12 u
12 u = 60
1 u = 60 ÷ 12 = 5
Number of people
= 15 u + 16 u + 4 u
= 35 u
= 35 x 5
= 175
Answer(s): 175