Two trains each 120 m long are moving in opposite directions. They cross each other in 15 seconds. If the speed of one train is 30 km/h, find the speed of the other train.
Answer & explanation
Correct answer: option 3
Total distance covered while crossing = 120 + 120 = 240 m
Time taken = 15 sec
Relative speed (S1 + S2) = \(\frac{Total\;Distance}{time}\) = \(\frac{240}{15}\) = \(\frac{48}{3}\) m/sec
= \(\frac{48}{3}\) × \(\frac{18}{5}\) km/hr = 57.6 km/hr
Speed of one train = 30 km/hr (given)
Speed of other train = 57.6 - 30 = 27.6 km/hr