Question

A train is running at a speed of$40km/hr$ and it crosses a post in$18seconds$. What is the length of the train?

• A. $190metres$
• B. $160metres$
• C. $200metres$
• D. $120metres$

Answer 1

The correct option is C

$200metres$

Step 1

Speed of a train

$$\begin{gathered} v=40km/hr \\ v=40000/3600m/s \\ v=400/36m/s \end{gathered}$$

Step 2

Time taken to cross,$t=18seconds$

Distance covered,$d=vt$

$d=(400/36)x18$

On calculating further, we get,

$$\begin{gathered} d=400/2 \\ d=200m \end{gathered}$$

Therefore, the length of the train is $200m$