Question

Two trains travel in the same direction at $50$ km/hr and $32$ km/hr, respectively. A man in the slower train observes that the faster train passes him completely in $15$ seconds. What is the length of the faster train in meters?

• A. $75$ m
• B. $50$ m
• C. $80$ m
• D. $60$ m

Answer 1

Answer: (A)

$75$ m

Since the trains travel in the same direction relative speed of the trains $=(50-32)$ km/hr $=18$ km/hr
$=(18\times \frac{5}{18})$ m/s $=5$ m/s
Therefore, length of the faster train $=$ Speed $\times$ Time $=(5\times 15)$ m $=75$ m