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 : 5. The ratio of the number of girls to boys in Team B is 3 : 5. There are 2 times as many contestants in Team B as in Team A. There are 10 more girls in Team B than Team A. What is the total number of contestants?
Team A |
Team B |
12 u |
8x3 = 24 u |
Girls |
Boys |
Girls |
Boys |
7 u |
5 u |
3x3 = 9 u |
5x3 = 15 u
|
Total number of contestants in Team A
= 7 u + 5 u
= 12 u
Total number of contestants in Team B
= 2 x 12 u
= 24 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 24 and 8 is 24.
Number of more girls in Team B than Team A
= 9 u - 7 u
= 2 u
2 u = 10
1 u = 10 ÷ 2 = 5
Total number of contestants
= 7 u + 5 u + 9 u + 15 u
= 36 u
= 36 x 5
= 180
Answer(s): 180