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 4 : 1. The ratio of the number of boys to girls in Team B is 7 : 3. There are 4 times as many pupils in Team B as in Team A. There are 110 more boys in Team B than Team A. What is the total number of pupils?
Team A |
Team B |
5 u |
10x2 = 20 u |
Boys |
Girls |
Boys |
Girls |
4 u |
1 u |
7x2 = 14 u |
3x2 = 6 u
|
Total number of pupils in Team A
= 4 u + 1 u
= 5 u
Total number of pupils in Team B
= 4 x 5 u
= 20 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 20 and 10 is 20.
Number of more boys in Team B than Team A
= 14 u - 4 u
= 10 u
10 u = 110
1 u = 110 ÷ 10 = 11
Total number of pupils
= 4 u + 1 u + 14 u + 6 u
= 25 u
= 25 x 11
= 275
Answer(s): 275