PSLE At a swimathon, each participant completed either a 2-km route, a 4-km route or a 7-km route.
13 of the participants completed the 2-km route,
27 of the participants completed the 4-km route and the rest completed the 7-km route. For every 1 km a participant swam, $5 was donated to charity. A total of $6580 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 4-km route to the number who completed the 7-km route?
- What is the total number of participants at the swimathon?
(a)
Fraction of the participants who completed 7-km route
= 1 -
13 -
27 = 1 -
721 -
621= 1 -
1321 =
821 Ratio of participants who completed the different routes
2 km : 4 km : 7 km
7 : 6 : 8
(b)
For every 1 km a participant swam, $5 was donated to charity.
Total distance covered by the participants
= 6580 ÷ 5
= 1316 km
|
2-km |
4-km |
7-km |
Total |
Number |
7 u |
6 u |
8 u |
21 u |
Value |
2 |
4 |
7 |
|
Total value |
14 u |
24 u |
56 u |
|
Total distance that the participants covered
= 2 x 7 u + 4 x 6 u + 7 x 8 u
= 14 u + 24 u + 56 u
= 94 u
94 u = 1316
1 u = 1316 ÷ 94 = 14
Total number of participants
= 7 u + 6 u + 8 u
= 21 u
= 21 x 14
= 294
Answer(s): (a) 7 : 6 : 8; (b) 294