Question

A train of length $100m$ travelling at $20m/s$ overtakes another of length $200m$ travelling at $10m/s$. The time taken by the first train to pass the second train is

• A. $30s$
• B. $50s$
• C. $10s$
• D. $40s$

Answer 1

The correct option is A $30s$

Distance covered by the first train to pass the second train $=(100+200)m=300m$
[since, both trains are travelling in the same direction]
and velocity of first train relative to second train $=(20-10)=10m/s$
$\therefore$ Time taken by the first train to pass the second train $=\frac{300}{10}=30s$