PSLE At a swimathon, each participant completed either a 2-km route, a 3-km route or a 6-km route.
16 of the participants completed the 2-km route,
23 of the participants completed the 3-km route and the rest completed the 6-km route. For every 1 km a participant swam, $5 was donated to charity. A total of $1200 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 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 -
23 = 1 -
16 -
46= 1 -
56 =
16 Ratio of participants who completed the different routes
2 km : 3 km : 6 km
1 : 4 : 1
(b)
For every 1 km a participant swam, $5 was donated to charity.
Total distance covered by the participants
= 1200 ÷ 5
= 240 km
|
2-km |
3-km |
6-km |
Total |
Number |
1 u |
4 u |
1 u |
6 u |
Value |
2 |
3 |
6 |
|
Total value |
2 u |
12 u |
6 u |
|
Total distance that the participants covered
= 2 x 1 u + 3 x 4 u + 6 x 1 u
= 2 u + 12 u + 6 u
= 20 u
20 u = 240
1 u = 240 ÷ 20 = 12
Total number of participants
= 1 u + 4 u + 1 u
= 6 u
= 6 x 12
= 72
Answer(s): (a) 1 : 4 : 1; (b) 72