PSLE At a swimathon, each participant completed either a 3-km route, a 5-km route or a 8-km route.
13 of the participants completed the 3-km route,
35 of the participants completed the 5-km route and the rest completed the 8-km route. For every 1 km a participant swam, $9 was donated to charity. A total of $7344 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 -
13 -
35 = 1 -
515 -
915= 1 -
1415 =
115 Ratio of participants who completed the different routes
3 km : 5 km : 8 km
5 : 9 : 1
(b)
For every 1 km a participant swam, $9 was donated to charity.
Total distance covered by the participants
= 7344 ÷ 9
= 816 km
|
3-km |
5-km |
8-km |
Total |
Number |
5 u |
9 u |
1 u |
15 u |
Value |
3 |
5 |
8 |
|
Total value |
15 u |
45 u |
8 u |
|
Total distance that the participants covered
= 3 x 5 u + 5 x 9 u + 8 x 1 u
= 15 u + 45 u + 8 u
= 68 u
68 u = 816
1 u = 816 ÷ 68 = 12
Total number of participants
= 5 u + 9 u + 1 u
= 15 u
= 15 x 12
= 180
Answer(s): (a) 5 : 9 : 1; (b) 180