PSLE The pupils at a school choir are divided in Team A and Team B. The ratio of the number of girls to boys in Team A is 6 : 1. The ratio of the number of girls to boys in Team B is 9 : 5. There are 4 times as many pupils in Team B as in Team A. There are 180 more girls in Team B than Team A. What is the total number of pupils?
Team A |
Team B |
7 u |
14x2 = 28 u |
Girls |
Boys |
Girls |
Boys |
6 u |
1 u |
9x2 = 18 u |
5x2 = 10 u
|
Total number of pupils in Team A
= 6 u + 1 u
= 7 u
Total number of pupils in Team B
= 4 x 7 u
= 28 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 28 and 14 is 28.
Number of more girls in Team B than Team A
= 18 u - 6 u
= 12 u
12 u = 180
1 u = 180 ÷ 12 = 15
Total number of pupils
= 6 u + 1 u + 18 u + 10 u
= 35 u
= 35 x 15
= 525
Answer(s): 525