PSLE At a walkathon, each participant completed either a 2-km route, a 4-km route or a 7-km route.
12 of the participants completed the 2-km route,
25 of the participants completed the 4-km route and the rest completed the 7-km route. For every 1 km a participant walked, $10 was donated to charity. A total of $3300 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 -
12 -
25 = 1 -
510 -
410= 1 -
910 =
110 Ratio of participants who completed the different routes
2 km : 4 km : 7 km
5 : 4 : 1
(b)
For every 1 km a participant walked, $10 was donated to charity.
Total distance covered by the participants
= 3300 ÷ 10
= 330 km
|
2-km |
4-km |
7-km |
Total |
Number |
5 u |
4 u |
1 u |
10 u |
Value |
2 |
4 |
7 |
|
Total value |
10 u |
16 u |
7 u |
|
Total distance that the participants covered
= 2 x 5 u + 4 x 4 u + 7 x 1 u
= 10 u + 16 u + 7 u
= 33 u
33 u = 330
1 u = 330 ÷ 33 = 10
Total number of participants
= 5 u + 4 u + 1 u
= 10 u
= 10 x 10
= 100
Answer(s): (a) 5 : 4 : 1; (b) 100