PSLE On Wednesday, the number of adults to girls to boys visiting a park was 1 : 4 : 5. On Thursday, the number of adults visiting the park remained the same. However, the number of girls increased by 50% and the number of boys decreased by 20%.
- What was the ratio of the number of adults to girls to boys visiting the park on Thursday?
- On Wednesday, 189 girls and boys visited the park. What was the total number of visitors at the park on Thursday?
|
Adults |
Girls |
Boys |
Before |
1 u |
4 u |
5 u |
Change |
|
+ 2 u |
- 1 u |
After |
1 u |
6 u |
4 u |
(a)
Increase in the number of girls
= 50% x 4 u
=
50100 x 4 u
= 2 u
Decrease in the number of boys
= 20% x 5 u
=
20100 x 5 u
= 1 u
Number of girls on Thursday
= 4 u + 2 u
= 6 u
Number of boys on Thursday
= 5 u - 1 u
= 4 u
On Thursday
Adults : Girls : Boys
1 : 6 : 4
(b)
Number of girls and boys on Wednesday
= 4 u + 5 u
= 9 u
9 u = 189
1 u = 189 ÷ 9 = 21
Total number of visitors on Thursday
= 1 u + 6 u + 4 u
= 11 u
= 11 x 21
= 231
Answer(s): (a) 1 : 6 : 4; (b) 231