In a school, the ratio of adults to the number of children is 5 : 9.
The ratio of the number of boys to the number of girls is 7 : 2.
There are 65 more boys than girls.
How many people are there in the school?
| Adults |
Children |
| 5 x 1 |
9 x 1 |
| |
Boys |
Girls |
| |
7 x 1 |
2 x 1 |
| 5 u |
7 u |
2 u |
The number of children is the combined repeated identity.
Make the number of children the same using the LCM of 9 and 9.
LCM of 9 and 9 = 9
Number of more boys than girls
= 7 u - 2 u
= 5 u
5 u = 65
1 u = 65 ÷ 5 = 13
Number of people
= 5 u + 7 u + 2 u
= 14 u
= 14 x 13
= 182
Answer(s): 182
