How to solve ?

2014-12-09 2:29 pm
Every day a cyclist meets a train at a particular crossing. The road is straight before the
crossing and both are traveling in the same direction. The cyclist travels with a speed of 10
Kmph. One day the cyclist comes late by 25 min. and meets the train 5km before the
crossing. What is the speed of the train?

回答 (2)

2014-12-09 5:32 pm
✔ 最佳答案
Suppose they normally reach the crossing together at 9:30
Today the cyclist will reach at 9:55, so @ 10 km/hr, (s)he will be 5 km away at 9:25.
The train still reaches at 9:30, so it covers 5 km in 5 mins
Thus speed of train = 1 km/min = 60 km/h <-----
2014-12-09 3:08 pm
Every day a cyclist meets a train at a particular crossing.
The road is straight before the crossing and both are traveling in the same direction.
The cyclist travels with a speed of 10 Kmph.
One day the cyclist comes late by 25 min. and meets the train 5 km before the crossing.
What is the speed of the train?
Cyclist and Train meet at 5 km point.
If cyclist had left on time, they would be 25 min at 10 km/h further 10 km/h * 25/60 h = 25/6 km
This leaves the cyclist 5/6 km from the cross road, when the train is at 5 km
Time cyclist takes to travel this 5/6 km = distance / speed
(5/6) / 10 = 1 / 12 hours
The train travels 5 km in 1/12 h
Speed = distance / time
5 / (1/12) = 5 * 12 = 60 km / h


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