PSLE On Tuesday, the number of adults to boys to girls visiting a zoo was 5 : 10 : 8. On Wednesday, the number of adults visiting the zoo remained the same. However, the number of boys decreased by 40% and the number of girls increased by 50%.
- What was the ratio of the number of children to adults visiting the zoo on Wednesday?
- On Tuesday, 738 boys and girls visited the zoo. What was the total number of child visitors at the zoo on Wednesday?
|
Adults |
Boys |
Girls |
Before |
5 u |
10 u |
8 u |
Change |
|
- 4 u |
+ 4 u |
After |
5 u |
6 u |
12 u |
(a)
Increase in the number of boys
= 40% x 10 u
=
40100 x 10 u
= 4 u
Decrease in the number of girls
= 50% x 8 u
=
50100 x 8 u
= 4 u
Number of boys on Wednesday
= 10 u - 4 u
= 6 u
Number of girls on Wednesday
= 8 u + 4 u
= 12 u
Number of children on Wednesday
= 6 u + 12 u
= 18 u
On Wednesday
Children : Adults
18 : 5
(b)
Number of boys and girls on Tuesday
= 10 u + 8 u
= 18 u
18 u = 738
1 u = 738 ÷ 18 = 41
Total number of child visitors on Wednesday
= 18 u
= 18 x 41
= 738
Answer(s): (a) 18 : 5; (b) 738