Last year, there were 170 members in a school concert club. The number of girls was
14 the number of boys.
- What percentage of the members were girls last year?
- This year, 1 boys left the club and 11 girls joined the club. What percentage of the members are girls this year?
(a)
Girls : Boys : Total
1 : 4 : 5
Percentage of members that were girls
=
15 x 100%
= 20%
(b)
|
Girls |
Boys |
Before |
1 u |
4 u |
Change |
+ 11 |
- 1 |
After |
1 u + 11 |
4 u - 1 |
5 u = 170
1 u = 170 ÷ 5 = 34
Number of girls this year
= 1 u + 11
= (1 x 34) + 11
= 34 + 11
= 45
Total members this year
= 170 + 11 - 1
= 180
Percentage of girls in the club
=
45180 x 100%
= 25%
Answer(s): (a) 20%; (b) 25%