PSLE The pupils at a camp are divided in Team A and Team B. The ratio of the number of boys to girls in Team A is 7 : 5. The ratio of the number of boys to girls in Team B is 5 : 1. There are 2 times as many pupils in Team B as in Team A. There are 39 more boys in Team B than Team A. What is the total number of pupils?
Team A |
Team B |
12 u |
6x4 = 24 u |
Boys |
Girls |
Boys |
Girls |
7 u |
5 u |
5x4 = 20 u |
1x4 = 4 u
|
Total number of pupils in Team A
= 7 u + 5 u
= 12 u
Total number of pupils in Team B
= 2 x 12 u
= 24 u
The total number of pupils in Team B is repeated.
Use LCM to make the total number of pupils in Team B the same.
LCM of 24 and 6 is 24.
Number of more boys in Team B than Team A
= 20 u - 7 u
= 13 u
13 u = 39
1 u = 39 ÷ 13 = 3
Total number of pupils
= 7 u + 5 u + 20 u + 4 u
= 36 u
= 36 x 3
= 108
Answer(s): 108