PSLE At a walkathon, each participant completed either a 1-km route, a 4-km route or a 7-km route.
23 of the participants completed the 1-km route,
15 of the participants completed the 4-km route and the rest completed the 7-km route. For every 1 km a participant walked, $6 was donated to charity. A total of $2808 was donated to charity.
- What is the ratio of the number of participants who completed the 1-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 walkathon?
(a)
Fraction of the participants who completed 7-km route
= 1 -
23 -
15 = 1 -
1015 -
315= 1 -
1315 =
215 Ratio of participants who completed the different routes
1 km : 4 km : 7 km
10 : 3 : 2
(b)
For every 1 km a participant walked, $6 was donated to charity.
Total distance covered by the participants
= 2808 ÷ 6
= 468 km
|
1-km |
4-km |
7-km |
Total |
Number |
10 u |
3 u |
2 u |
15 u |
Value |
1 |
4 |
7 |
|
Total value |
10 u |
12 u |
14 u |
|
Total distance that the participants covered
= 1 x 10 u + 4 x 3 u + 7 x 2 u
= 10 u + 12 u + 14 u
= 36 u
36 u = 468
1 u = 468 ÷ 36 = 13
Total number of participants
= 10 u + 3 u + 2 u
= 15 u
= 15 x 13
= 195
Answer(s): (a) 10 : 3 : 2; (b) 195