PSLE At a walkathon, each participant completed either a 3-km route, a 6-km route or a 7-km route.
15 of the participants completed the 3-km route,
23 of the participants completed the 6-km route and the rest completed the 7-km route. For every 1 km a participant walked, $5 was donated to charity. A total of $6640 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 7-km route?
- What is the total number of participants at the walkathon?
(a)
Fraction of the participants who completed 7-km route
= 1 -
15 -
23 = 1 -
315 -
1015= 1 -
1315 =
215 Ratio of participants who completed the different routes
3 km : 6 km : 7 km
3 : 10 : 2
(b)
For every 1 km a participant walked, $5 was donated to charity.
Total distance covered by the participants
= 6640 ÷ 5
= 1328 km
|
3-km |
6-km |
7-km |
Total |
Number |
3 u |
10 u |
2 u |
15 u |
Value |
3 |
6 |
7 |
|
Total value |
9 u |
60 u |
14 u |
|
Total distance that the participants covered
= 3 x 3 u + 6 x 10 u + 7 x 2 u
= 9 u + 60 u + 14 u
= 83 u
83 u = 1328
1 u = 1328 ÷ 83 = 16
Total number of participants
= 3 u + 10 u + 2 u
= 15 u
= 15 x 16
= 240
Answer(s): (a) 3 : 10 : 2; (b) 240