PSLE At a swimathon, each participant completed either a 1-km route, a 3-km route or a 4-km route.
12 of the participants completed the 1-km route,
49 of the participants completed the 3-km route and the rest completed the 4-km route. For every 1 km a participant swam, $5 was donated to charity. A total of $3515 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 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 -
12 -
49 = 1 -
918 -
818= 1 -
1718 =
118 Ratio of participants who completed the different routes
1 km : 3 km : 4 km
9 : 8 : 1
(b)
For every 1 km a participant swam, $5 was donated to charity.
Total distance covered by the participants
= 3515 ÷ 5
= 703 km
|
1-km |
3-km |
4-km |
Total |
Number |
9 u |
8 u |
1 u |
18 u |
Value |
1 |
3 |
4 |
|
Total value |
9 u |
24 u |
4 u |
|
Total distance that the participants covered
= 1 x 9 u + 3 x 8 u + 4 x 1 u
= 9 u + 24 u + 4 u
= 37 u
37 u = 703
1 u = 703 ÷ 37 = 19
Total number of participants
= 9 u + 8 u + 1 u
= 18 u
= 18 x 19
= 342
Answer(s): (a) 9 : 8 : 1; (b) 342