PSLE
The students at a sports meet are divided in Group A and Group B. The ratio of the number of boys to girls in Group A is 4 : 3. The ratio of the number of boys to girls in Group B is 11 : 3. There are 4 times as many students in Group B as in Group A. There are 162 less boys in Group A than Group B. What is the total number of students in Group A?

Group A		Group B
7 u		14x2 = 28 u
Boys	Girls	Boys	Girls
4 u	3 u	11x2 = 22 u	3x2 = 6 u

Total number of students in Group A
= 4 u + 3 u
= 7 u

Total number of students in Group B
= 4 x 7 u
= 28 u

The total number of students in Group B is repeated.
Use LCM to make the total number of students in Group B the same.
LCM of 28 and 14 is 28.

Number of less boys in Group A than Group B
= 22 u - 4 u
= 18 u

18 u = 162

1 u = 162 ÷ 18 = 9

Total number of students in Group A
= 4 u + 3 u
= 7 u
= 7 x 9
= 63

Answer(s): 63