A train takes 6 sec and 5 sec to cross two men who are walking in opposite direction at the speed of 5 m/sec and 10 m/sec respectively. Find length of the train.

150 m

Train passes first person in 6 sec.

Let the length of Train is L and speed is S

\(\frac{L}{S+5}\) = 6

L = 6(S + 5) ..... (i)

Train passes the other person in 5 sec. 

\(\frac{L}{S+10}\) = 5

L = 5(S + 10) ..... (ii)

From equation (i) and (ii)

6(S + 5) = 5(S + 10)

⇒ 6S + 30 = 5S + 50

S = 20 m/sec

Put the value of S in equation (i)

L = 6(20 + 5) = 150 m