In a school, the ratio of adults to the number of children is 8 : 7.
The ratio of the number of boys to the number of girls is 6 : 1.
There are 60 less girls than boys.
How many people are there in the school?
| Adults |
Children |
| 8 x 1 |
7 x 1 |
| |
Boys |
Girls |
| |
6 x 1 |
1 x 1 |
| 8 u |
6 u |
1 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 less girls than boys
= 6 u - 1 u
= 5 u
5 u = 60
1 u = 60 ÷ 5 = 12
Number of people
= 8 u + 6 u + 1 u
= 15 u
= 15 x 12
= 180
Answer(s): 180
