PSLE At a walkathon, each participant completed either a 1-km route, a 2-km route or a 4-km route.
15 of the participants completed the 1-km route,
715 of the participants completed the 2-km route and the rest completed the 4-km route. For every 1 km a participant walked, $10 was donated to charity. A total of $5180 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 2-km route to the number who completed the 4-km route?
- What is the total number of participants at the walkathon?
(a)
Fraction of the participants who completed 4-km route
= 1 -
15 -
715 = 1 -
315 -
715= 1 -
1015 =
515 Ratio of participants who completed the different routes
1 km : 2 km : 4 km
3 : 7 : 5
(b)
For every 1 km a participant walked, $10 was donated to charity.
Total distance covered by the participants
= 5180 ÷ 10
= 518 km
|
1-km |
2-km |
4-km |
Total |
Number |
3 u |
7 u |
5 u |
15 u |
Value |
1 |
2 |
4 |
|
Total value |
3 u |
14 u |
20 u |
|
Total distance that the participants covered
= 1 x 3 u + 2 x 7 u + 4 x 5 u
= 3 u + 14 u + 20 u
= 37 u
37 u = 518
1 u = 518 ÷ 37 = 14
Total number of participants
= 3 u + 7 u + 5 u
= 15 u
= 15 x 14
= 210
Answer(s): (a) 3 : 7 : 5; (b) 210