A man in a train notices that he can count 21 telephone posts in one minute. If they are known to be 50 metres apart, at what speed is the train travelling?
61 km/hr
56 km/hr
63 km/hr
60 km/hr
Explanation:
The man can count 21 telephone posts in one minute. Number of gaps between 21 posts is 20 and adjacent posts are 50 metres apart.
It means 20×50=1000 metres are covered in 1 minute.
distance =1000 m=1 km
time =1 min=1/60 hr
speed =1/(1/60)=60 km/hr
The man can count 21 telephone posts in one minute. Number of gaps between 21 posts is 20 and adjacent posts are 50 metres apart.
It means 20×50=1000 metres are covered in 1 minute.
distance =1000 m=1 km
time =1 min=1/60 hr
speed =1/(1/60)=60 km/hr