PSLE The contestants at a contest 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 4 : 1. There are 5 times as many contestants in Team B as in Team A. There are 78 less girls in Team A than Team B. What is the total number of contestants in Team A?
Team A |
Team B |
4 u |
5x4 = 20 u |
Girls |
Boys |
Girls |
Boys |
3 u |
1 u |
4x4 = 16 u |
1x4 = 4 u
|
Total number of contestants in Team A
= 3 u + 1 u
= 4 u
Total number of contestants in Team B
= 5 x 4 u
= 20 u
The total number of contestants in Team B is repeated.
Use LCM to make the total number of contestants in Team B the same.
LCM of 20 and 5 is 20.
Number of less girls in Team A than Team B
= 16 u - 3 u
= 13 u
13 u = 78
1 u = 78 ÷ 13 = 6
Total number of contestants in Team A
= 3 u + 1 u
= 4 u
= 4 x 6
= 24
Answer(s): 24