Question

A $60m$ long train moving with constant speed on a straight level track passes a pole in $5s$. The time it will take to cross a $540m$ long bridge is:

• A. 50

Answer 1

The correct option is A 50
Given:
Length of the train $=60m$
Length of the bridge $=540m$
Time taken to cross the pole $=5s$

Speed of the train $=$

$⟹\frac{\text{Length of the train}}{\text{Time taken to cross the pole}}$

$⟹\frac{60}{5}m/s=12m/s$

Now, distance to be covered to cross a $540m$ long bridge:

$⟹$ Length of the train + Length of the bridge

$⟹60m+540m=600m$

Hence, time taken $=\frac{\text{distance}}{\text{speed}}$
$⟹\frac{600}{12}s$ $=50s$