PSLE At a walkathon, each participant completed either a 2-km route, a 3-km route or a 4-km route.
15 of the participants completed the 2-km route,
920 of the participants completed the 3-km route and the rest completed the 4-km route. For every 1 km a participant walked, $5 was donated to charity. A total of $3150 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 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 -
15 -
920 = 1 -
420 -
920= 1 -
1320 =
720 Ratio of participants who completed the different routes
2 km : 3 km : 4 km
4 : 9 : 7
(b)
For every 1 km a participant walked, $5 was donated to charity.
Total distance covered by the participants
= 3150 ÷ 5
= 630 km
|
2-km |
3-km |
4-km |
Total |
Number |
4 u |
9 u |
7 u |
20 u |
Value |
2 |
3 |
4 |
|
Total value |
8 u |
27 u |
28 u |
|
Total distance that the participants covered
= 2 x 4 u + 3 x 9 u + 4 x 7 u
= 8 u + 27 u + 28 u
= 63 u
63 u = 630
1 u = 630 ÷ 63 = 10
Total number of participants
= 4 u + 9 u + 7 u
= 20 u
= 20 x 10
= 200
Answer(s): (a) 4 : 9 : 7; (b) 200