PSLE At a swimathon, each participant completed either a 2-km route, a 4-km route or a 7-km route.
16 of the participants completed the 2-km route,
29 of the participants completed the 4-km route and the rest completed the 7-km route. For every 1 km a participant swam, $5 was donated to charity. A total of $6435 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 4-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 -
16 -
29 = 1 -
318 -
418= 1 -
718 =
1118 Ratio of participants who completed the different routes
2 km : 4 km : 7 km
3 : 4 : 11
(b)
For every 1 km a participant swam, $5 was donated to charity.
Total distance covered by the participants
= 6435 ÷ 5
= 1287 km
|
2-km |
4-km |
7-km |
Total |
Number |
3 u |
4 u |
11 u |
18 u |
Value |
2 |
4 |
7 |
|
Total value |
6 u |
16 u |
77 u |
|
Total distance that the participants covered
= 2 x 3 u + 4 x 4 u + 7 x 11 u
= 6 u + 16 u + 77 u
= 99 u
99 u = 1287
1 u = 1287 ÷ 99 = 13
Total number of participants
= 3 u + 4 u + 11 u
= 18 u
= 18 x 13
= 234
Answer(s): (a) 3 : 4 : 11; (b) 234