PSLE
The students at a sports meet 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 5 : 1. There are 3 times as many students in Team B as in Team A. There are 84 less girls in Team A than Team B. What is the total number of students in Team A?

Team A		Team B
4 u		6x2 = 12 u
Girls	Boys	Girls	Boys
3 u	1 u	5x2 = 10 u	1x2 = 2 u

Total number of students in Team A
= 3 u + 1 u
= 4 u

Total number of students in Team B
= 3 x 4 u
= 12 u

The total number of students in Team B is repeated.
Use LCM to make the total number of students in Team B the same.
LCM of 12 and 6 is 12.

Number of less girls in Team A than Team B
= 10 u - 3 u
= 7 u

7 u = 84

1 u = 84 ÷ 7 = 12

Total number of students in Team A
= 3 u + 1 u
= 4 u
= 4 x 12
= 48

Answer(s): 48