PSLE At a walkathon, each participant completed either a 1-km route, a 4-km route or a 7-km route.
13 of the participants completed the 1-km route,
310 of the participants completed the 4-km route and the rest completed the 7-km route. For every 1 km a participant walked, $8 was donated to charity. A total of $14760 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 4-km route to the number who completed the 7-km route?
- What is the total number of participants at the walkathon?
(a)
Fraction of the participants who completed 7-km route
= 1 -
13 -
310 = 1 -
1030 -
930= 1 -
1930 =
1130 Ratio of participants who completed the different routes
1 km : 4 km : 7 km
10 : 9 : 11
(b)
For every 1 km a participant walked, $8 was donated to charity.
Total distance covered by the participants
= 14760 ÷ 8
= 1845 km
|
1-km |
4-km |
7-km |
Total |
Number |
10 u |
9 u |
11 u |
30 u |
Value |
1 |
4 |
7 |
|
Total value |
10 u |
36 u |
77 u |
|
Total distance that the participants covered
= 1 x 10 u + 4 x 9 u + 7 x 11 u
= 10 u + 36 u + 77 u
= 123 u
123 u = 1845
1 u = 1845 ÷ 123 = 15
Total number of participants
= 10 u + 9 u + 11 u
= 30 u
= 30 x 15
= 450
Answer(s): (a) 10 : 9 : 11; (b) 450