PSLE On Monday, the number of adults to boys to girls visiting a park was 3 : 10 : 10. On Tuesday, the number of adults visiting the park remained the same. However, the number of boys increased by 50% and the number of girls decreased by 30%.
- What was the ratio of the number of adults to boys to girls visiting the park on Tuesday?
- On Monday, 480 boys and girls visited the park. What was the total number of visitors at the park on Tuesday?
|
Adults |
Boys |
Girls |
Before |
3 u |
10 u |
10 u |
Change |
|
+ 5 u |
- 3 u |
After |
3 u |
15 u |
7 u |
(a)
Increase in the number of boys
= 50% x 10 u
=
50100 x 10 u
= 5 u
Decrease in the number of girls
= 30% x 10 u
=
30100 x 10 u
= 3 u
Number of boys on Tuesday
= 10 u + 5 u
= 15 u
Number of girls on Tuesday
= 10 u - 3 u
= 7 u
On Tuesday
Adults : Boys : Girls
3 : 15 : 7
(b)
Number of boys and girls on Monday
= 10 u + 10 u
= 20 u
20 u = 480
1 u = 480 ÷ 20 = 24
Total number of visitors on Tuesday
= 3 u + 15 u + 7 u
= 25 u
= 25 x 24
= 600
Answer(s): (a) 3 : 15 : 7; (b) 600