PSLE At a walkathon, each participant completed either a 2-km route, a 4-km route or a 7-km route.
13 of the participants completed the 2-km route,
512 of the participants completed the 4-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 $3185 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 7-km route?
- What is the total number of participants at the walkathon?
(a)
Fraction of the participants who completed 7-km route
= 1 -
13 -
512 = 1 -
412 -
512= 1 -
912 =
312 Ratio of participants who completed the different routes
2 km : 4 km : 7 km
4 : 5 : 3
(b)
For every 1 km a participant walked, $5 was donated to charity.
Total distance covered by the participants
= 3185 ÷ 5
= 637 km
|
2-km |
4-km |
7-km |
Total |
Number |
4 u |
5 u |
3 u |
12 u |
Value |
2 |
4 |
7 |
|
Total value |
8 u |
20 u |
21 u |
|
Total distance that the participants covered
= 2 x 4 u + 4 x 5 u + 7 x 3 u
= 8 u + 20 u + 21 u
= 49 u
49 u = 637
1 u = 637 ÷ 49 = 13
Total number of participants
= 4 u + 5 u + 3 u
= 12 u
= 12 x 13
= 156
Answer(s): (a) 4 : 5 : 3; (b) 156