PSLE On Saturday, the number of adults to boys to girls visiting a bird park was 7 : 12 : 10. On Sunday, the number of adults visiting the bird park remained the same. However, the number of boys increased by 50% and the number of girls decreased by 20%.
- What was the ratio of the number of adults to boys to girls visiting the bird park on Sunday?
- On Saturday, 462 boys and girls visited the bird park. What was the total number of visitors at the bird park on Sunday?
|
Adults |
Boys |
Girls |
Before |
7 u |
12 u |
10 u |
Change |
|
+ 6 u |
- 2 u |
After |
7 u |
18 u |
8 u |
(a)
Increase in the number of boys
= 50% x 12 u
=
50100 x 12 u
= 6 u
Decrease in the number of girls
= 20% x 10 u
=
20100 x 10 u
= 2 u
Number of boys on Sunday
= 12 u + 6 u
= 18 u
Number of girls on Sunday
= 10 u - 2 u
= 8 u
On Sunday
Adults : Boys : Girls
7 : 18 : 8
(b)
Number of boys and girls on Saturday
= 12 u + 10 u
= 22 u
22 u = 462
1 u = 462 ÷ 22 = 21
Total number of visitors on Sunday
= 7 u + 18 u + 8 u
= 33 u
= 33 x 21
= 693
Answer(s): (a) 7 : 18 : 8; (b) 693