PSLE At a walkathon, each participant completed either a 3-km route, a 5-km route or a 8-km route.
12 of the participants completed the 3-km route,
13 of the participants completed the 5-km route and the rest completed the 8-km route. For every 1 km a participant walked, $8 was donated to charity. A total of $4320 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 5-km route to the number who completed the 8-km route?
- What is the total number of participants at the walkathon?
(a)
Fraction of the participants who completed 8-km route
= 1 -
12 -
13 = 1 -
36 -
26= 1 -
56 =
16 Ratio of participants who completed the different routes
3 km : 5 km : 8 km
3 : 2 : 1
(b)
For every 1 km a participant walked, $8 was donated to charity.
Total distance covered by the participants
= 4320 ÷ 8
= 540 km
|
3-km |
5-km |
8-km |
Total |
Number |
3 u |
2 u |
1 u |
6 u |
Value |
3 |
5 |
8 |
|
Total value |
9 u |
10 u |
8 u |
|
Total distance that the participants covered
= 3 x 3 u + 5 x 2 u + 8 x 1 u
= 9 u + 10 u + 8 u
= 27 u
27 u = 540
1 u = 540 ÷ 27 = 20
Total number of participants
= 3 u + 2 u + 1 u
= 6 u
= 6 x 20
= 120
Answer(s): (a) 3 : 2 : 1; (b) 120