PSLE At a swimathon, each participant completed either a 2-km route, a 4-km route or a 6-km route.
14 of the participants completed the 2-km route,
25 of the participants completed the 4-km route and the rest completed the 6-km route. For every 1 km a participant swam, $8 was donated to charity. A total of $9408 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 6-km route?
- What is the total number of participants at the swimathon?
(a)
Fraction of the participants who completed 6-km route
= 1 -
14 -
25 = 1 -
520 -
820= 1 -
1320 =
720 Ratio of participants who completed the different routes
2 km : 4 km : 6 km
5 : 8 : 7
(b)
For every 1 km a participant swam, $8 was donated to charity.
Total distance covered by the participants
= 9408 ÷ 8
= 1176 km
|
2-km |
4-km |
6-km |
Total |
Number |
5 u |
8 u |
7 u |
20 u |
Value |
2 |
4 |
6 |
|
Total value |
10 u |
32 u |
42 u |
|
Total distance that the participants covered
= 2 x 5 u + 4 x 8 u + 6 x 7 u
= 10 u + 32 u + 42 u
= 84 u
84 u = 1176
1 u = 1176 ÷ 84 = 14
Total number of participants
= 5 u + 8 u + 7 u
= 20 u
= 20 x 14
= 280
Answer(s): (a) 5 : 8 : 7; (b) 280