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 3 : 1. The ratio of the number of girls to boys in Team B is 3 : 7. There are 5 times as many pupils in Team B as in Team A. There are 6 less girls in Team A than Team B. What is the total number of pupils in Team A?
Team A |
Team B |
4 u |
10x2 = 20 u |
Girls |
Boys |
Girls |
Boys |
3 u |
1 u |
3x2 = 6 u |
7x2 = 14 u
|
Total number of pupils in Team A
= 3 u + 1 u
= 4 u
Total number of pupils in Team B
= 5 x 4 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 less girls in Team A than Team B
= 6 u - 3 u
= 3 u
3 u = 6
1 u = 6 ÷ 3 = 2
Total number of pupils in Team A
= 3 u + 1 u
= 4 u
= 4 x 2
= 8
Answer(s): 8