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. 60% of the girls and 20% of the boys are in Team N. The rest of the pupils are in Team P.
- What is the ratio of the number of pupils in Team P to Team N? Give your answer in the simplest form.
- The number of boys in Team N is more than 60. What is the smallest possible total number of pupils taking part in the quiz?
Girls |
Boys |
10 u |
40 u |
Team N |
Team P |
Team N |
Team P |
6 u |
4 u |
8 u |
32 u |
(a)
Girls : Boys
1 : 4
10 : 40
Number of girls in Team N
= 60% x 10 u
=
60100 x 10 u
= 6 u
Number of girls in Team P
= 10 u - 6 u
= 4 u
Number of boys in Team N
= 20% x 40 u
=
20100 x 40 u
= 8 u
Number of boys in Team P
= 40 u - 8 u
= 32 u
Team N : Team P
4 + 32 : 6 + 8
36 : 14
(÷2)18 : 7
(b)
Number of boys in Team N = 8 u
Since the number of boys in Team N is 8 u, it must be multiple of 8.
Number of sets of 8
= 60 ÷ 8
= 7 r 4
Since the number of boys in Team N is more than 60, the number of sets must be 1 more than 7.
1 u = 7 + 1 = 8
Smallest possible number of pupils
= 10 u + 40 u
= 50 u
= 50 x 8
= 400
Answer(s): (a) 18 : 7; (b) 400