PSLE On Friday, the number of adults to girls to boys visiting a bird park was 7 : 4 : 10. On Saturday, the number of adults visiting the bird park remained the same. However, the number of girls increased by 50% and the number of boys decreased by 50%.
- What was the ratio of the number of adults to girls to boys visiting the bird park on Saturday?
- On Friday, 434 girls and boys visited the bird park. What was the total number of visitors at the bird park on Saturday?
|
Adults |
Girls |
Boys |
Before |
7 u |
4 u |
10 u |
Change |
|
+ 2 u |
- 5 u |
After |
7 u |
6 u |
5 u |
(a)
Increase in the number of girls
= 50% x 4 u
=
50100 x 4 u
= 2 u
Decrease in the number of boys
= 50% x 10 u
=
50100 x 10 u
= 5 u
Number of girls on Saturday
= 4 u + 2 u
= 6 u
Number of boys on Saturday
= 10 u - 5 u
= 5 u
On Saturday
Adults : Girls : Boys
7 : 6 : 5
(b)
Number of girls and boys on Friday
= 4 u + 10 u
= 14 u
14 u = 434
1 u = 434 ÷ 14 = 31
Total number of visitors on Saturday
= 7 u + 6 u + 5 u
= 18 u
= 18 x 31
= 558
Answer(s): (a) 7 : 6 : 5; (b) 558