PSLE
The number of girls and boys taking part in a contest are in the ratio 3 : 4. These students are put into two teams. 60% of the girls and 20% of the boys are in Team F. The rest of the students are in Team G.

1. What is the ratio of the number of students in Team G to Team F? Give your answer in the simplest form.
2. The number of girls in Team G is fewer than 70. What is the largest possible total number of students taking part in the contest?

Girls		Boys
30 u		40 u
Team F	Team G	Team F	Team G
18 u	12 u	8 u	32 u

(a)
Girls : Boys
3 : 4
30 : 40

Number of girls in Team F
= 60% x 30 u
= ⁶⁰₁₀₀ x 30 u
= 18 u

Number of girls in Team G
= 30 u - 18 u
= 12 u

Number of boys in Team F
= 20% x 40 u
= ²⁰₁₀₀ x 40 u
= 8 u

Number of boys in Team G
= 40 u - 8 u
= 32 u

Team G : Team F
12 + 32 : 18 + 8
44 : 26 _(÷2)
22 : 13

(b)
Number of girls in Team G = 12 u

Since the number of girls in Team G is 12 u, it must be multiple of 12.

Number of sets of 12
= 70 ÷ 12
= 5 r 10

Since the number of girls in Team G is less than 70, the number of sets must be 5.

1 u = 5

Largest possible number of students
= 30 u + 40 u
= 70 u
= 70 x 5
= 350

Answer(s): (a) 22 : 13; (b) 350