PSLE At a swimathon, each participant completed either a 3-km route, a 6-km route or a 9-km route.
16 of the participants completed the 3-km route,
29 of the participants completed the 6-km route and the rest completed the 9-km route. For every 1 km a participant swam, $5 was donated to charity. A total of $10560 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 6-km route to the number who completed the 9-km route?
- What is the total number of participants at the swimathon?
(a)
Fraction of the participants who completed 9-km route
= 1 -
16 -
29 = 1 -
318 -
418= 1 -
718 =
1118 Ratio of participants who completed the different routes
3 km : 6 km : 9 km
3 : 4 : 11
(b)
For every 1 km a participant swam, $5 was donated to charity.
Total distance covered by the participants
= 10560 ÷ 5
= 2112 km
|
3-km |
6-km |
9-km |
Total |
Number |
3 u |
4 u |
11 u |
18 u |
Value |
3 |
6 |
9 |
|
Total value |
9 u |
24 u |
99 u |
|
Total distance that the participants covered
= 3 x 3 u + 6 x 4 u + 9 x 11 u
= 9 u + 24 u + 99 u
= 132 u
132 u = 2112
1 u = 2112 ÷ 132 = 16
Total number of participants
= 3 u + 4 u + 11 u
= 18 u
= 18 x 16
= 288
Answer(s): (a) 3 : 4 : 11; (b) 288