Trains P and Q are running in the same direction on parallel tracks with speeds of x km/h and 90 km/h (90 > x), respectively. The faster train passes a man sitting in the slower train in 30 seconds. If the length of train Q is 225 m, then what is the value of x?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 63.
Relative speed = (90 - x) km/h
(90 - x) × (5/18) × 30 = 225
⇒ 90 - x = 27
⇒ x = 90 - 27 = 63 km/h