Question

A man sitting in a train travelling at the rate of 50 km/hr observes that it takes 9 sec for a goods train travelling in the opposite direction to pass him. If the goods train in 187.5 m long, find its speed.

• A. 40 km/hr
• B. 25 km/hr
• C. 35 km/hr
• D. 36 km/hr

Answer 1

Answer: (B)

25 km/hr

Answer 2

Formula for time take = $\frac{Distance}{Speed}$
Time taken = $\frac{Distance(length \ of\ train)}{Relative\ Speed}$
Let speed of the train be v km/hr
According to the formula
$\frac{9}{3600}$ = $\frac{0.1875}{[50+v]}$
On solving the above equation,
we get v = 25 km/hr
The correct option is (B)