PSLE At a walkathon, each participant completed either a 3-km route, a 4-km route or a 5-km route.
14 of the participants completed the 3-km route,
720 of the participants completed the 4-km route and the rest completed the 5-km route. For every 1 km a participant walked, $5 was donated to charity. A total of $4150 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 4-km route to the number who completed the 5-km route?
- What is the total number of participants at the walkathon?
(a)
Fraction of the participants who completed 5-km route
= 1 -
14 -
720 = 1 -
520 -
720= 1 -
1220 =
820 Ratio of participants who completed the different routes
3 km : 4 km : 5 km
5 : 7 : 8
(b)
For every 1 km a participant walked, $5 was donated to charity.
Total distance covered by the participants
= 4150 ÷ 5
= 830 km
|
3-km |
4-km |
5-km |
Total |
Number |
5 u |
7 u |
8 u |
20 u |
Value |
3 |
4 |
5 |
|
Total value |
15 u |
28 u |
40 u |
|
Total distance that the participants covered
= 3 x 5 u + 4 x 7 u + 5 x 8 u
= 15 u + 28 u + 40 u
= 83 u
83 u = 830
1 u = 830 ÷ 83 = 10
Total number of participants
= 5 u + 7 u + 8 u
= 20 u
= 20 x 10
= 200
Answer(s): (a) 5 : 7 : 8; (b) 200