PSLE
The number of girls and boys taking part in a quiz are in the ratio 1 : 4. These pupils are put into two teams. 20% of the girls and 50% of the boys are in Team G. The rest of the pupils are in Team H.

1. What is the ratio of the number of pupils in Team H to Team G? Give your answer in the simplest form.
2. The number of girls in Team H is fewer than 50. What is the largest possible total number of pupils taking part in the quiz?

Girls		Boys
10 u		40 u
Team G	Team H	Team G	Team H
2 u	8 u	20 u	20 u

(a)
Girls : Boys
1 : 4
10 : 40

Number of girls in Team G
= 20% x 10 u
= ²⁰₁₀₀ x 10 u
= 2 u

Number of girls in Team H
= 10 u - 2 u
= 8 u

Number of boys in Team G
= 50% x 40 u
= ⁵⁰₁₀₀ x 40 u
= 20 u

Number of boys in Team H
= 40 u - 20 u
= 20 u

Team H : Team G
8 + 20 : 2 + 20
28 : 22 _(÷2)
14 : 11

(b)
Number of girls in Team H = 8 u

Since the number of girls in Team H is 8 u, it must be multiple of 8.

Number of sets of 8
= 50 ÷ 8
= 6 r 2

Since the number of girls in Team H is less than 50, the number of sets must be 6.

1 u = 6

Largest possible number of pupils
= 10 u + 40 u
= 50 u
= 50 x 6
= 300

Answer(s): (a) 14 : 11; (b) 300