A 815 m long train crosses a man walking at a speed of 2.7 km/h in the oppositedirection in 18 seconds. What is the speed (in km/h) of the train?

Correct option is B

Given:

Length of the train = 815 meters

Speed of the man = 2.7 km/h

Time taken to cross the man = 18 seconds

We need to find the speed of the train in km/h.

Formula Used:​

Speed = $$\frac{\text{Distance}}{\text{Time}}$$​​

Solution:

Convert the speed of the man to m/s:

$$= \frac{2.7 \times 1000}{3600} = \frac{3}{4} \, \text{m/s}$$​​

Now, 

Train Speed + $$\frac{3}{4}$$​ m/s = $$\frac{815}{18}$$​​

Train Speed = $$\frac{815}{18} - \frac{3}{4}$$​​

​$$= \frac{3260 - 54}{18 \times 4}$$​​

​$$= \frac{3206}{18\times4}\ m/s$$​​

In km/h,

​$$= \frac{3206}{18\times4} \times \frac{18}{5}$$​​

= 160.3 km/h