PSLE The pupils at a school choir are divided in Team A and Team B. The ratio of the number of boys to girls in Team A is 3 : 1. The ratio of the number of boys to girls in Team B is 3 : 5. There are 4 times as many pupils in Team B as in Team A. There are 30 more boys in Team B than Team A. What is the total number of pupils?
Team A |
Team B |
4 u |
8x2 = 16 u |
Boys |
Girls |
Boys |
Girls |
3 u |
1 u |
3x2 = 6 u |
5x2 = 10 u
|
Total number of pupils in Team A
= 3 u + 1 u
= 4 u
Total number of pupils in Team B
= 4 x 4 u
= 16 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 16 and 8 is 16.
Number of more boys in Team B than Team A
= 6 u - 3 u
= 3 u
3 u = 30
1 u = 30 ÷ 3 = 10
Total number of pupils
= 3 u + 1 u + 6 u + 10 u
= 20 u
= 20 x 10
= 200
Answer(s): 200