Question

How long does a train $110$ metres long running at the speed of $72km/$ hr take to cross a bridge $132$ metres in length ?

• A. $9.8$ sec
• B. $12.1$ sec
• C. $12.42$ sec
• D. $14.3$ sec

Answer 1

The correct option is B $12.1$ sec

The length of the train $=110m$

Speed of the train

$=72km/hr$

$=72\times \frac{5}{18}=20m/s$

The length of the bridge $=132m$

Time taken by train to cross the bridge

$=\frac{110+132}{20}$

$=\frac{242}{20}$

$=12.1\sec$

Hence, this is the answer.