PSLE The number of girls and boys taking part in a test are in the ratio 4 : 3. These pupils are put into two teams. 20% of the girls and 60% of the boys are in Team E. The rest of the pupils are in Team F.
- What is the ratio of the number of pupils in Team F to Team E? Give your answer in the simplest form.
- The number of girls in Team F is fewer than 80. What is the largest possible total number of pupils taking part in the test?
Girls |
Boys |
40 u |
30 u |
Team E |
Team F |
Team E |
Team F |
8 u |
32 u |
18 u |
12 u |
(a)
Girls : Boys
4 : 3
40 : 30
Number of girls in Team E
= 20% x 40 u
=
20100 x 40 u
= 8 u
Number of girls in Team F
= 40 u - 8 u
= 32 u
Number of boys in Team E
= 60% x 30 u
=
60100 x 30 u
= 18 u
Number of boys in Team F
= 30 u - 18 u
= 12 u
Team F : Team E
32 + 12 : 8 + 18
44 : 26
(÷2)22 : 13
(b)
Number of girls in Team F = 32 u
Since the number of girls in Team F is 32 u, it must be multiple of 32.
Number of sets of 32
= 80 ÷ 32
= 2 r 16
Since the number of girls in Team F is less than 80, the number of sets must be 2.
1 u = 2
Largest possible number of pupils
= 40 u + 30 u
= 70 u
= 70 x 2
= 140
Answer(s): (a) 22 : 13; (b) 140