PSLE On Thursday, the number of adults to boys to girls visiting a theme park was 3 : 8 : 2. On Friday, the number of adults visiting the theme park remained the same. However, the number of boys increased by 50% and the number of girls decreased by 50%.
- What was the ratio of the number of adults to boys to girls visiting the theme park on Friday?
- On Thursday, 210 boys and girls visited the theme park. What was the total number of visitors at the theme park on Friday?
|
Adults |
Boys |
Girls |
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 boys
= 50% x 8 u
=
50100 x 8 u
= 4 u
Decrease in the number of girls
= 50% x 2 u
=
50100 x 2 u
= 1 u
Number of boys on Friday
= 8 u + 4 u
= 12 u
Number of girls on Friday
= 2 u - 1 u
= 1 u
On Friday
Adults : Boys : Girls
3 : 12 : 1
(b)
Number of boys and girls on Thursday
= 8 u + 2 u
= 10 u
10 u = 210
1 u = 210 ÷ 10 = 21
Total number of visitors on Friday
= 3 u + 12 u + 1 u
= 16 u
= 16 x 21
= 336
Answer(s): (a) 3 : 12 : 1; (b) 336