The lengths of two trains are 380 m and 220 m. The faster of these two trains takes 20 seconds to overtake the other when traveling in the same direction. The trains take 12 seconds to cross each other when travelling in opposite directions. What is the speed (in km/h) of the faster train?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 144.
Speed of faster train = a m/s
Speed of slower train = b m/s
Total distance to cover = 380 + 220 = 600 m
a - b = 600/20 = 30 m/s .....(1)
a + b = 600/12 = 50 m/s .....(2)
From (1) and (2): a = 80 ⇒ Va = 40 m/s = 144 km/h