PSLE At a swimathon, each participant completed either a 1-km route, a 3-km route or a 4-km route.
13 of the participants completed the 1-km route,
310 of the participants completed the 3-km route and the rest completed the 4-km route. For every 1 km a participant swam, $10 was donated to charity. A total of $15390 was donated to charity.
- What is the ratio of the number of participants who completed the 1-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 -
310 = 1 -
1030 -
930= 1 -
1930 =
1130 Ratio of participants who completed the different routes
1 km : 3 km : 4 km
10 : 9 : 11
(b)
For every 1 km a participant swam, $10 was donated to charity.
Total distance covered by the participants
= 15390 ÷ 10
= 1539 km
|
1-km |
3-km |
4-km |
Total |
Number |
10 u |
9 u |
11 u |
30 u |
Value |
1 |
3 |
4 |
|
Total value |
10 u |
27 u |
44 u |
|
Total distance that the participants covered
= 1 x 10 u + 3 x 9 u + 4 x 11 u
= 10 u + 27 u + 44 u
= 81 u
81 u = 1539
1 u = 1539 ÷ 81 = 19
Total number of participants
= 10 u + 9 u + 11 u
= 30 u
= 30 x 19
= 570
Answer(s): (a) 10 : 9 : 11; (b) 570