PSLE At a walkathon, each participant completed either a 3-km route, a 4-km route or a 7-km route.
13 of the participants completed the 3-km route,
47 of the participants completed the 4-km route and the rest completed the 7-km route. For every 1 km a participant walked, $6 was donated to charity. A total of $6474 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 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 -
13 -
47 = 1 -
721 -
1221= 1 -
1921 =
221 Ratio of participants who completed the different routes
3 km : 4 km : 7 km
7 : 12 : 2
(b)
For every 1 km a participant walked, $6 was donated to charity.
Total distance covered by the participants
= 6474 ÷ 6
= 1079 km
|
3-km |
4-km |
7-km |
Total |
Number |
7 u |
12 u |
2 u |
21 u |
Value |
3 |
4 |
7 |
|
Total value |
21 u |
48 u |
14 u |
|
Total distance that the participants covered
= 3 x 7 u + 4 x 12 u + 7 x 2 u
= 21 u + 48 u + 14 u
= 83 u
83 u = 1079
1 u = 1079 ÷ 83 = 13
Total number of participants
= 7 u + 12 u + 2 u
= 21 u
= 21 x 13
= 273
Answer(s): (a) 7 : 12 : 2; (b) 273