PSLE On Friday, the number of adults to girls to boys visiting a zoo was 5 : 12 : 6. On Saturday, the number of adults visiting the zoo 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 zoo on Saturday?
- On Friday, 576 girls and boys visited the zoo. What was the total number of visitors at the zoo on Saturday?
|
Adults |
Girls |
Boys |
Before |
5 u |
12 u |
6 u |
Change |
|
+ 6 u |
- 3 u |
After |
5 u |
18 u |
3 u |
(a)
Increase in the number of girls
= 50% x 12 u
=
50100 x 12 u
= 6 u
Decrease in the number of boys
= 50% x 6 u
=
50100 x 6 u
= 3 u
Number of girls on Saturday
= 12 u + 6 u
= 18 u
Number of boys on Saturday
= 6 u - 3 u
= 3 u
On Saturday
Adults : Girls : Boys
5 : 18 : 3
(b)
Number of girls and boys on Friday
= 12 u + 6 u
= 18 u
18 u = 576
1 u = 576 ÷ 18 = 32
Total number of visitors on Saturday
= 5 u + 18 u + 3 u
= 26 u
= 26 x 32
= 832
Answer(s): (a) 5 : 18 : 3; (b) 832