saswata4s wrote:

A man driving a car at a speed of 50 miles/hour on a road parallel to a railway track noticed a train coming from opposite direction. It took 4 seconds for the car to pass the train. If the length of the train was 0.1 miles and the length of the car was negligible, what was the speed of the train?

(a) 40

(b) 60

(c) 70

(d) 80

(e) 90

Let speed of the train be \(x\). So relative speed \(= 50+x\)

so distance traveled, \((50+x)*\frac{4}{3600}=0.1\) (speed * time = distance)

or \(x=40\)

Option

A