A train, 300m long, passed a man, walking along the line in the same direction at the rate of 3 kmph in 33 seconds. The speed of the train is:

Answer: Option D

Let the speed of train = x km/ hr
Length of train = 300 metres
Their relative speed in same direction
= (x - 3) km/hr
According to the question,
$$\frac{\left(300+0\right)m}{\left(x-3\right)\times \frac{5}{18}m/s}=33$$
[Here man's length is 0 metre]
$$\begin{array}{rl}& \frac{100\times 18}{5x-15}=11\\ & 1800=55x-165\\ & 55x=1965\end{array}$$
∴ Speed of the train = $$\frac{1965}{55}$$  = $$35\frac{8}{11}$$  kmph