PSLE At a walkathon, each participant completed either a 3-km route, a 5-km route or a 7-km route.
12 of the participants completed the 3-km route,
513 of the participants completed the 5-km route and the rest completed the 7-km route. For every 1 km a participant walked, $9 was donated to charity. A total of $11880 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 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 -
513 = 1 -
1326 -
1026= 1 -
2326 =
326 Ratio of participants who completed the different routes
3 km : 5 km : 7 km
13 : 10 : 3
(b)
For every 1 km a participant walked, $9 was donated to charity.
Total distance covered by the participants
= 11880 ÷ 9
= 1320 km
|
3-km |
5-km |
7-km |
Total |
Number |
13 u |
10 u |
3 u |
26 u |
Value |
3 |
5 |
7 |
|
Total value |
39 u |
50 u |
21 u |
|
Total distance that the participants covered
= 3 x 13 u + 5 x 10 u + 7 x 3 u
= 39 u + 50 u + 21 u
= 110 u
110 u = 1320
1 u = 1320 ÷ 110 = 12
Total number of participants
= 13 u + 10 u + 3 u
= 26 u
= 26 x 12
= 312
Answer(s): (a) 13 : 10 : 3; (b) 312