PSLE On Saturday, the number of adults to girls to boys visiting a park was 3 : 8 : 2. On Sunday, 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 50%.
- What was the ratio of the number of adults to girls to boys visiting the park on Sunday?
- On Saturday, 320 girls and boys visited the park. What was the total number of visitors at the park on Sunday?
|
Adults |
Girls |
Boys |
Before |
3 u |
8 u |
2 u |
Change |
|
+ 4 u |
- 1 u |
After |
3 u |
12 u |
1 u |
(a)
Increase in the number of girls
= 50% x 8 u
=
50100 x 8 u
= 4 u
Decrease in the number of boys
= 50% x 2 u
=
50100 x 2 u
= 1 u
Number of girls on Sunday
= 8 u + 4 u
= 12 u
Number of boys on Sunday
= 2 u - 1 u
= 1 u
On Sunday
Adults : Girls : Boys
3 : 12 : 1
(b)
Number of girls and boys on Saturday
= 8 u + 2 u
= 10 u
10 u = 320
1 u = 320 ÷ 10 = 32
Total number of visitors on Sunday
= 3 u + 12 u + 1 u
= 16 u
= 16 x 32
= 512
Answer(s): (a) 3 : 12 : 1; (b) 512