PSLE At a walkathon, each participant completed either a 2-km route, a 4-km route or a 7-km route.
15 of the participants completed the 2-km route,
310 of the participants completed the 4-km route and the rest completed the 7-km route. For every 1 km a participant walked, $7 was donated to charity. A total of $6783 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 -
15 -
310 = 1 -
210 -
310= 1 -
510 =
510 Ratio of participants who completed the different routes
2 km : 4 km : 7 km
2 : 3 : 5
(b)
For every 1 km a participant walked, $7 was donated to charity.
Total distance covered by the participants
= 6783 ÷ 7
= 969 km
|
2-km |
4-km |
7-km |
Total |
Number |
2 u |
3 u |
5 u |
10 u |
Value |
2 |
4 |
7 |
|
Total value |
4 u |
12 u |
35 u |
|
Total distance that the participants covered
= 2 x 2 u + 4 x 3 u + 7 x 5 u
= 4 u + 12 u + 35 u
= 51 u
51 u = 969
1 u = 969 ÷ 51 = 19
Total number of participants
= 2 u + 3 u + 5 u
= 10 u
= 10 x 19
= 190
Answer(s): (a) 2 : 3 : 5; (b) 190