Correct Answer - Option 5 : 24 kmph
Given:
⇒ Speed of passenger train = 60kmph = 60 × 5/18 = 50/3 m/s
Calculation:
Let length of platform be a m.
⇒ (a + 180)/(50/3) = 18
⇒ a = 120 m
Let speed of Goods train be p m/s.
⇒ (150 + 120)/27 = p
⇒ p = 10 m/s
∴ Relative speed of two trains = 50/3 - 10 = 20/3 m/s = 20/3 × 18/5 = 24 kmph