PSLE On Wednesday, the number of adults to boys to girls visiting a theme park was 7 : 10 : 10. On Thursday, the number of adults visiting the theme park remained the same. However, the number of boys increased by 20% and the number of girls decreased by 40%.
- What was the ratio of the number of adults to boys to girls visiting the theme park on Thursday?
- On Wednesday, 520 boys and girls visited the theme park. What was the total number of visitors at the theme park on Thursday?
|
Adults |
Boys |
Girls |
Before |
7 u |
10 u |
10 u |
Change |
|
+ 2 u |
- 4 u |
After |
7 u |
12 u |
6 u |
(a)
Increase in the number of boys
= 20% x 10 u
=
20100 x 10 u
= 2 u
Decrease in the number of girls
= 40% x 10 u
=
40100 x 10 u
= 4 u
Number of boys on Thursday
= 10 u + 2 u
= 12 u
Number of girls on Thursday
= 10 u - 4 u
= 6 u
On Thursday
Adults : Boys : Girls
7 : 12 : 6
(b)
Number of boys and girls on Wednesday
= 10 u + 10 u
= 20 u
20 u = 520
1 u = 520 ÷ 20 = 26
Total number of visitors on Thursday
= 7 u + 12 u + 6 u
= 25 u
= 25 x 26
= 650
Answer(s): (a) 7 : 12 : 6; (b) 650