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,
411 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 $7875 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 -
411 = 1 -
1122 -
822= 1 -
1922 =
322 Ratio of participants who completed the different routes
2 km : 4 km : 7 km
11 : 8 : 3
(b)
For every 1 km a participant walked, $7 was donated to charity.
Total distance covered by the participants
= 7875 ÷ 7
= 1125 km
|
2-km |
4-km |
7-km |
Total |
Number |
11 u |
8 u |
3 u |
22 u |
Value |
2 |
4 |
7 |
|
Total value |
22 u |
32 u |
21 u |
|
Total distance that the participants covered
= 2 x 11 u + 4 x 8 u + 7 x 3 u
= 22 u + 32 u + 21 u
= 75 u
75 u = 1125
1 u = 1125 ÷ 75 = 15
Total number of participants
= 11 u + 8 u + 3 u
= 22 u
= 22 x 15
= 330
Answer(s): (a) 11 : 8 : 3; (b) 330