PSLE At a swimathon, each participant completed either a 2-km route, a 5-km route or a 6-km route.
12 of the participants completed the 2-km route,
49 of the participants completed the 5-km route and the rest completed the 6-km route. For every 1 km a participant swam, $6 was donated to charity. A total of $7680 was donated to charity.
- What is the ratio of the number of participants who completed the 2-km route to the number who completed the 5-km route to the number who completed the 6-km route?
- What is the total number of participants at the swimathon?
(a)
Fraction of the participants who completed 6-km route
= 1 -
12 -
49 = 1 -
918 -
818= 1 -
1718 =
118 Ratio of participants who completed the different routes
2 km : 5 km : 6 km
9 : 8 : 1
(b)
For every 1 km a participant swam, $6 was donated to charity.
Total distance covered by the participants
= 7680 ÷ 6
= 1280 km
|
2-km |
5-km |
6-km |
Total |
Number |
9 u |
8 u |
1 u |
18 u |
Value |
2 |
5 |
6 |
|
Total value |
18 u |
40 u |
6 u |
|
Total distance that the participants covered
= 2 x 9 u + 5 x 8 u + 6 x 1 u
= 18 u + 40 u + 6 u
= 64 u
64 u = 1280
1 u = 1280 ÷ 64 = 20
Total number of participants
= 9 u + 8 u + 1 u
= 18 u
= 18 x 20
= 360
Answer(s): (a) 9 : 8 : 1; (b) 360