Question

In what time will a train $100$ meters long with a speed of $50$ km/hr cross a pillar ?

• A. $7$ seconds
• B. $72$ seconds
• C. $7.2$ seconds
• D. $70$ seconds

Answer 1

Answer: (C)

$7.2$ seconds

Speed of the train $=50$ km/hr $=$ $50\times \frac{5}{18}$ m/sec $=$ $\frac{125}{9}$ m/sec
Distance travelled $=$ Length of train $=100$ m
$\therefore$ Time taken to cross the pillar $=$ $\frac{100}{125/9}$ seconds $=$ $\frac{36}{5}$ seconds $=7.2$ sec