PSLE At a swimathon, each participant completed either a 1-km route, a 4-km route or a 6-km route.
16 of the participants completed the 1-km route,
12 of the participants completed the 4-km route and the rest completed the 6-km route. For every 1 km a participant swam, $6 was donated to charity. A total of $3000 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 4-km route to the number who completed the 6-km route?
- What is the total number of participants at the swimathon?
(a)
Fraction of the participants who completed 6-km route
= 1 -
16 -
12 = 1 -
16 -
36= 1 -
46 =
26 Ratio of participants who completed the different routes
1 km : 4 km : 6 km
1 : 3 : 2
(b)
For every 1 km a participant swam, $6 was donated to charity.
Total distance covered by the participants
= 3000 ÷ 6
= 500 km
|
1-km |
4-km |
6-km |
Total |
Number |
1 u |
3 u |
2 u |
6 u |
Value |
1 |
4 |
6 |
|
Total value |
1 u |
12 u |
12 u |
|
Total distance that the participants covered
= 1 x 1 u + 4 x 3 u + 6 x 2 u
= 1 u + 12 u + 12 u
= 25 u
25 u = 500
1 u = 500 ÷ 25 = 20
Total number of participants
= 1 u + 3 u + 2 u
= 6 u
= 6 x 20
= 120
Answer(s): (a) 1 : 3 : 2; (b) 120