PSLE At a walkathon, each participant completed either a 1-km route, a 3-km route or a 4-km route.
12 of the participants completed the 1-km route,
518 of the participants completed the 3-km route and the rest completed the 4-km route. For every 1 km a participant walked, $9 was donated to charity. A total of $7200 was donated to charity.
- What is the ratio of the number of participants who completed the 1-km route to the number who completed the 3-km route to the number who completed the 4-km route?
- What is the total number of participants at the walkathon?
(a)
Fraction of the participants who completed 4-km route
= 1 -
12 -
518 = 1 -
918 -
518= 1 -
1418 =
418 Ratio of participants who completed the different routes
1 km : 3 km : 4 km
9 : 5 : 4
(b)
For every 1 km a participant walked, $9 was donated to charity.
Total distance covered by the participants
= 7200 ÷ 9
= 800 km
|
1-km |
3-km |
4-km |
Total |
Number |
9 u |
5 u |
4 u |
18 u |
Value |
1 |
3 |
4 |
|
Total value |
9 u |
15 u |
16 u |
|
Total distance that the participants covered
= 1 x 9 u + 3 x 5 u + 4 x 4 u
= 9 u + 15 u + 16 u
= 40 u
40 u = 800
1 u = 800 ÷ 40 = 20
Total number of participants
= 9 u + 5 u + 4 u
= 18 u
= 18 x 20
= 360
Answer(s): (a) 9 : 5 : 4; (b) 360