PSLE At a swimathon, each participant completed either a 3-km route, a 4-km route or a 5-km route.
13 of the participants completed the 3-km route,
415 of the participants completed the 4-km route and the rest completed the 5-km route. For every 1 km a participant swam, $8 was donated to charity. A total of $7808 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 4-km route to the number who completed the 5-km route?
- What is the total number of participants at the swimathon?
(a)
Fraction of the participants who completed 5-km route
= 1 -
13 -
415 = 1 -
515 -
415= 1 -
915 =
615 Ratio of participants who completed the different routes
3 km : 4 km : 5 km
5 : 4 : 6
(b)
For every 1 km a participant swam, $8 was donated to charity.
Total distance covered by the participants
= 7808 ÷ 8
= 976 km
|
3-km |
4-km |
5-km |
Total |
Number |
5 u |
4 u |
6 u |
15 u |
Value |
3 |
4 |
5 |
|
Total value |
15 u |
16 u |
30 u |
|
Total distance that the participants covered
= 3 x 5 u + 4 x 4 u + 5 x 6 u
= 15 u + 16 u + 30 u
= 61 u
61 u = 976
1 u = 976 ÷ 61 = 16
Total number of participants
= 5 u + 4 u + 6 u
= 15 u
= 15 x 16
= 240
Answer(s): (a) 5 : 4 : 6; (b) 240