Two trains running in opposite directions cross a man standing on the platform in 42 seconds and 28 seconds respectively and they cross each other in 35 seconds. The ratio of their speeds is

Question: Two trains running in opposite directions cross a man standing on the platform in 42 seconds and 28 seconds respectively and they cross each other in 35 seconds. The ratio of their speeds is

Solution:
Let,
Speed of the faster train = x ms^-1
Speed of slower train = y ms^-1
Length of faster train = 42x m
Length of slower train = 28y m

According to the question,
(42x + 28y)/(x + y) = 35
⇒ 42x + 28y = 35x + 35y
⇒ 42x - 35x =35y - 28y
⇒ 7x = 7y
⇒ x/y = 7/7
⇒ x : y = 1 : 1