PSLE
The students at a sports meet are divided in Team A and Team B. The ratio of the number of boys to girls in Team A is 6 : 1. The ratio of the number of boys to girls in Team B is 13 : 1. There are 4 times as many students in Team B as in Team A. There are 80 more boys in Team B than Team A. What is the total number of students?

Team A		Team B
7 u		14x2 = 28 u
Boys	Girls	Boys	Girls
6 u	1 u	13x2 = 26 u	1x2 = 2 u

Total number of students in Team A
= 6 u + 1 u
= 7 u

Total number of students in Team B
= 4 x 7 u
= 28 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 28 and 14 is 28.

Number of more boys in Team B than Team A
= 26 u - 6 u
= 20 u

20 u = 80

1 u = 80 ÷ 20 = 4

Total number of students
= 6 u + 1 u + 26 u + 2 u
= 35 u
= 35 x 4
= 140

Answer(s): 140