PSLE The pupils at a camp are divided in Group A and Group B. The ratio of the number of girls to boys in Group A is 4 : 3. The ratio of the number of girls to boys in Group B is 13 : 1. There are 4 times as many pupils in Group B as in Group A. There are 110 more girls in Group B than Group A. What is the total number of pupils?
Group A |
Group B |
7 u |
14x2 = 28 u |
Girls |
Boys |
Girls |
Boys |
4 u |
3 u |
13x2 = 26 u |
1x2 = 2 u
|
Total number of pupils in Group A
= 4 u + 3 u
= 7 u
Total number of pupils in Group B
= 4 x 7 u
= 28 u
The total number of pupils in Group B is repeated.
Use LCM to make the total number of pupils in Group B the same.
LCM of 28 and 14 is 28.
Number of more girls in Group B than Group A
= 26 u - 4 u
= 22 u
22 u = 110
1 u = 110 ÷ 22 = 5
Total number of pupils
= 4 u + 3 u + 26 u + 2 u
= 35 u
= 35 x 5
= 175
Answer(s): 175