PSLE At a swimathon, each participant completed either a 3-km route, a 4-km route or a 5-km route.
14 of the participants completed the 3-km route,
712 of the participants completed the 4-km route and the rest completed the 5-km route. For every 1 km a participant swam, $10 was donated to charity. A total of $7990 was donated to charity.
- What is the ratio of the number of participants who completed the 3-km route to the number who completed the 4-km route to the number who completed the 5-km route?
- What is the total number of participants at the swimathon?
(a)
Fraction of the participants who completed 5-km route
= 1 -
14 -
712 = 1 -
312 -
712= 1 -
1012 =
212 Ratio of participants who completed the different routes
3 km : 4 km : 5 km
3 : 7 : 2
(b)
For every 1 km a participant swam, $10 was donated to charity.
Total distance covered by the participants
= 7990 ÷ 10
= 799 km
|
3-km |
4-km |
5-km |
Total |
Number |
3 u |
7 u |
2 u |
12 u |
Value |
3 |
4 |
5 |
|
Total value |
9 u |
28 u |
10 u |
|
Total distance that the participants covered
= 3 x 3 u + 4 x 7 u + 5 x 2 u
= 9 u + 28 u + 10 u
= 47 u
47 u = 799
1 u = 799 ÷ 47 = 17
Total number of participants
= 3 u + 7 u + 2 u
= 12 u
= 12 x 17
= 204
Answer(s): (a) 3 : 7 : 2; (b) 204