PSLE At a walkathon, each participant completed either a 2-km route, a 4-km route or a 5-km route.
13 of the participants completed the 2-km route,
47 of the participants completed the 4-km route and the rest completed the 5-km route. For every 1 km a participant walked, $10 was donated to charity. A total of $13680 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 5-km route?
- What is the total number of participants at the walkathon?
(a)
Fraction of the participants who completed 5-km route
= 1 -
13 -
47 = 1 -
721 -
1221= 1 -
1921 =
221 Ratio of participants who completed the different routes
2 km : 4 km : 5 km
7 : 12 : 2
(b)
For every 1 km a participant walked, $10 was donated to charity.
Total distance covered by the participants
= 13680 ÷ 10
= 1368 km
|
2-km |
4-km |
5-km |
Total |
Number |
7 u |
12 u |
2 u |
21 u |
Value |
2 |
4 |
5 |
|
Total value |
14 u |
48 u |
10 u |
|
Total distance that the participants covered
= 2 x 7 u + 4 x 12 u + 5 x 2 u
= 14 u + 48 u + 10 u
= 72 u
72 u = 1368
1 u = 1368 ÷ 72 = 19
Total number of participants
= 7 u + 12 u + 2 u
= 21 u
= 21 x 19
= 399
Answer(s): (a) 7 : 12 : 2; (b) 399