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 7 : 3. The ratio of the number of girls to boys in Team B is 3 : 1. There are 2 times as many contestants in Team B as in Team A. There are 80 more girls in Team B than Team A. What is the total number of contestants?
Team A |
Team B |
10 u |
4x5 = 20 u |
Girls |
Boys |
Girls |
Boys |
7 u |
3 u |
3x5 = 15 u |
1x5 = 5 u
|
Total number of contestants in Team A
= 7 u + 3 u
= 10 u
Total number of contestants in Team B
= 2 x 10 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 4 is 20.
Number of more girls in Team B than Team A
= 15 u - 7 u
= 8 u
8 u = 80
1 u = 80 ÷ 8 = 10
Total number of contestants
= 7 u + 3 u + 15 u + 5 u
= 30 u
= 30 x 10
= 300
Answer(s): 300