PSLE At a swimathon, each participant completed either a 3-km route, a 5-km route or a 8-km route.
25 of the participants completed the 3-km route,
12 of the participants completed the 5-km route and the rest completed the 8-km route. For every 1 km a participant swam, $7 was donated to charity. A total of $6300 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 5-km route to the number who completed the 8-km route?
- What is the total number of participants at the swimathon?
(a)
Fraction of the participants who completed 8-km route
= 1 -
25 -
12 = 1 -
410 -
510= 1 -
910 =
110 Ratio of participants who completed the different routes
3 km : 5 km : 8 km
4 : 5 : 1
(b)
For every 1 km a participant swam, $7 was donated to charity.
Total distance covered by the participants
= 6300 ÷ 7
= 900 km
|
3-km |
5-km |
8-km |
Total |
Number |
4 u |
5 u |
1 u |
10 u |
Value |
3 |
5 |
8 |
|
Total value |
12 u |
25 u |
8 u |
|
Total distance that the participants covered
= 3 x 4 u + 5 x 5 u + 8 x 1 u
= 12 u + 25 u + 8 u
= 45 u
45 u = 900
1 u = 900 ÷ 45 = 20
Total number of participants
= 4 u + 5 u + 1 u
= 10 u
= 10 x 20
= 200
Answer(s): (a) 4 : 5 : 1; (b) 200