PSLE At a swimathon, each participant completed either a 3-km route, a 6-km route or a 7-km route.
14 of the participants completed the 3-km route,
920 of the participants completed the 6-km route and the rest completed the 7-km route. For every 1 km a participant swam, $10 was donated to charity. A total of $11100 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 6-km route to the number who completed the 7-km route?
- What is the total number of participants at the swimathon?
(a)
Fraction of the participants who completed 7-km route
= 1 -
14 -
920 = 1 -
520 -
920= 1 -
1420 =
620 Ratio of participants who completed the different routes
3 km : 6 km : 7 km
5 : 9 : 6
(b)
For every 1 km a participant swam, $10 was donated to charity.
Total distance covered by the participants
= 11100 ÷ 10
= 1110 km
|
3-km |
6-km |
7-km |
Total |
Number |
5 u |
9 u |
6 u |
20 u |
Value |
3 |
6 |
7 |
|
Total value |
15 u |
54 u |
42 u |
|
Total distance that the participants covered
= 3 x 5 u + 6 x 9 u + 7 x 6 u
= 15 u + 54 u + 42 u
= 111 u
111 u = 1110
1 u = 1110 ÷ 111 = 10
Total number of participants
= 5 u + 9 u + 6 u
= 20 u
= 20 x 10
= 200
Answer(s): (a) 5 : 9 : 6; (b) 200