Question

A train $110$ m long passes a man running at a speed of $6$ km/hr in the direction opposite to the train in $6$ seconds. What is the speed of the train?

• A. $90$ km/hr
• B. $80$ km/hr
• C. $60$ km/hr
• D. $50$ km/hr

Answer 1

Answer: (C)

$60$ km/hr

Let the speed of the train be $x$ km/hr
Speed of man $=6$ km/hr
Since the train and the man are in opposite directions
Relative speed $=(x+6)$ km/hr $=\left(\right(x+6)\times \frac{5}{18})$ m/s
Therefore, $(x+6)\times \frac{5}{18}\times 6=110$

$\Rightarrow 5x+30=330$

$\Rightarrow 5x=300$

$\Rightarrow x=60$ km/hr