PSLE At a swimathon, each participant completed either a 2-km route, a 3-km route or a 4-km route.
23 of the participants completed the 2-km route,
15 of the participants completed the 3-km route and the rest completed the 4-km route. For every 1 km a participant swam, $8 was donated to charity. A total of $3552 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 swimathon?
(a)
Fraction of the participants who completed 4-km route
= 1 -
23 -
15 = 1 -
1015 -
315= 1 -
1315 =
215 Ratio of participants who completed the different routes
2 km : 3 km : 4 km
10 : 3 : 2
(b)
For every 1 km a participant swam, $8 was donated to charity.
Total distance covered by the participants
= 3552 ÷ 8
= 444 km
|
2-km |
3-km |
4-km |
Total |
Number |
10 u |
3 u |
2 u |
15 u |
Value |
2 |
3 |
4 |
|
Total value |
20 u |
9 u |
8 u |
|
Total distance that the participants covered
= 2 x 10 u + 3 x 3 u + 4 x 2 u
= 20 u + 9 u + 8 u
= 37 u
37 u = 444
1 u = 444 ÷ 37 = 12
Total number of participants
= 10 u + 3 u + 2 u
= 15 u
= 15 x 12
= 180
Answer(s): (a) 10 : 3 : 2; (b) 180