PSLE At a swimathon, each participant completed either a 2-km route, a 3-km route or a 4-km route.
13 of the participants completed the 2-km route,
15 of the participants completed the 3-km route and the rest completed the 4-km route. For every 1 km a participant swam, $7 was donated to charity. A total of $5593 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 4-km route?
- What is the total number of participants at the swimathon?
(a)
Fraction of the participants who completed 4-km route
= 1 -
13 -
15 = 1 -
515 -
315= 1 -
815 =
715 Ratio of participants who completed the different routes
2 km : 3 km : 4 km
5 : 3 : 7
(b)
For every 1 km a participant swam, $7 was donated to charity.
Total distance covered by the participants
= 5593 ÷ 7
= 799 km
|
2-km |
3-km |
4-km |
Total |
Number |
5 u |
3 u |
7 u |
15 u |
Value |
2 |
3 |
4 |
|
Total value |
10 u |
9 u |
28 u |
|
Total distance that the participants covered
= 2 x 5 u + 3 x 3 u + 4 x 7 u
= 10 u + 9 u + 28 u
= 47 u
47 u = 799
1 u = 799 ÷ 47 = 17
Total number of participants
= 5 u + 3 u + 7 u
= 15 u
= 15 x 17
= 255
Answer(s): (a) 5 : 3 : 7; (b) 255