In a school, the ratio of adults to the number of children is 1 : 2.
The ratio of the number of boys to the number of girls is 2 : 1.
There are 30 more boys than girls.
How many people are there in the school?
Adults |
Children |
1 x 3 |
2 x 3 |
|
Boys |
Girls |
|
2 x 2 |
1 x 2 |
3 u |
4 u |
2 u |
The number of children is the combined repeated identity.
Make the number of children the same using the LCM of 2 and 3.
LCM of 2 and 3 = 6
Number of more boys than girls
= 4 u - 2 u
= 2 u
2 u = 30
1 u = 30 ÷ 2 = 15
Number of people
= 3 u + 4 u + 2 u
= 9 u
= 9 x 15
= 135
Answer(s): 135