Two trains one 120 m and 180 m long are running in opposite direction on a parallel track at the speed of 51 km/hr and 57 km/hr respectively. How long will they take to cross each other?
Answer & explanation
Correct answer: option 3
Total distance traveled to cross each other = 120 + 180 = 300m
Relative speed in opposite direction = 51 + 57 = 108 km/hr = 108 × \(\frac{5}{18}\) m/sec = 30 m/sec
Time taken to cross = \(\frac{Total\;Distance}{Relative\;Speed}\) = \(\frac{300}{30}\) = 10 Sec.