PSLE At a walkathon, each participant completed either a 1-km route, a 2-km route or a 3-km route.
12 of the participants completed the 1-km route,
49 of the participants completed the 2-km route and the rest completed the 3-km route. For every 1 km a participant walked, $10 was donated to charity. A total of $5320 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 2-km route to the number who completed the 3-km route?
- What is the total number of participants at the walkathon?
(a)
Fraction of the participants who completed 3-km route
= 1 -
12 -
49 = 1 -
918 -
818= 1 -
1718 =
118 Ratio of participants who completed the different routes
1 km : 2 km : 3 km
9 : 8 : 1
(b)
For every 1 km a participant walked, $10 was donated to charity.
Total distance covered by the participants
= 5320 ÷ 10
= 532 km
|
1-km |
2-km |
3-km |
Total |
Number |
9 u |
8 u |
1 u |
18 u |
Value |
1 |
2 |
3 |
|
Total value |
9 u |
16 u |
3 u |
|
Total distance that the participants covered
= 1 x 9 u + 2 x 8 u + 3 x 1 u
= 9 u + 16 u + 3 u
= 28 u
28 u = 532
1 u = 532 ÷ 28 = 19
Total number of participants
= 9 u + 8 u + 1 u
= 18 u
= 18 x 19
= 342
Answer(s): (a) 9 : 8 : 1; (b) 342