PSLE At a swimathon, each participant completed either a 1-km route, a 2-km route or a 5-km route.
14 of the participants completed the 1-km route,
720 of the participants completed the 2-km route and the rest completed the 5-km route. For every 1 km a participant swam, $5 was donated to charity. A total of $5310 was donated to charity.
- What is the ratio of the number of participants who completed the 1-km route to the number who completed the 2-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 -
720 = 1 -
520 -
720= 1 -
1220 =
820 Ratio of participants who completed the different routes
1 km : 2 km : 5 km
5 : 7 : 8
(b)
For every 1 km a participant swam, $5 was donated to charity.
Total distance covered by the participants
= 5310 ÷ 5
= 1062 km
|
1-km |
2-km |
5-km |
Total |
Number |
5 u |
7 u |
8 u |
20 u |
Value |
1 |
2 |
5 |
|
Total value |
5 u |
14 u |
40 u |
|
Total distance that the participants covered
= 1 x 5 u + 2 x 7 u + 5 x 8 u
= 5 u + 14 u + 40 u
= 59 u
59 u = 1062
1 u = 1062 ÷ 59 = 18
Total number of participants
= 5 u + 7 u + 8 u
= 20 u
= 20 x 18
= 360
Answer(s): (a) 5 : 7 : 8; (b) 360