PSLE The number of girls and boys taking part in a contest are in the ratio 3 : 5. These pupils are put into two teams. 50% of the girls and 10% of the boys are in Team L. The rest of the pupils are in Team M.
- What is the ratio of the number of pupils in Team M to Team L? Give your answer in the simplest form.
- The number of girls in Team M is fewer than 40. What is the largest possible total number of pupils taking part in the contest?
Girls |
Boys |
30 u |
50 u |
Team L |
Team M |
Team L |
Team M |
15 u |
15 u |
5 u |
45 u |
(a)
Girls : Boys
3 : 5
30 : 50
Number of girls in Team L
= 50% x 30 u
=
50100 x 30 u
= 15 u
Number of girls in Team M
= 30 u - 15 u
= 15 u
Number of boys in Team L
= 10% x 50 u
=
10100 x 50 u
= 5 u
Number of boys in Team M
= 50 u - 5 u
= 45 u
Team M : Team L
15 + 45 : 15 + 5
60 : 20
(÷20)3 : 1
(b)
Number of girls in Team M = 15 u
Since the number of girls in Team M is 15 u, it must be multiple of 15.
Number of sets of 15
= 40 ÷ 15
= 2 r 10
Since the number of girls in Team M is less than 40, the number of sets must be 2.
1 u = 2
Largest possible number of pupils
= 30 u + 50 u
= 80 u
= 80 x 2
= 160
Answer(s): (a) 3 : 1; (b) 160