PSLE At a walkathon, each participant completed either a 1-km route, a 4-km route or a 7-km route.
14 of the participants completed the 1-km route,
35 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 $7400 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 -
14 -
35 = 1 -
520 -
1220= 1 -
1720 =
320 Ratio of participants who completed the different routes
1 km : 4 km : 7 km
5 : 12 : 3
(b)
For every 1 km a participant walked, $5 was donated to charity.
Total distance covered by the participants
= 7400 ÷ 5
= 1480 km
|
1-km |
4-km |
7-km |
Total |
Number |
5 u |
12 u |
3 u |
20 u |
Value |
1 |
4 |
7 |
|
Total value |
5 u |
48 u |
21 u |
|
Total distance that the participants covered
= 1 x 5 u + 4 x 12 u + 7 x 3 u
= 5 u + 48 u + 21 u
= 74 u
74 u = 1480
1 u = 1480 ÷ 74 = 20
Total number of participants
= 5 u + 12 u + 3 u
= 20 u
= 20 x 20
= 400
Answer(s): (a) 5 : 12 : 3; (b) 400