Correct Answer - Option 5 : 9 second
Given:
Speed of the first train (S1) = 100 km/h
Speed of another train (S2) = 104 km/h
Length of the first train (L1) = 250 m
Length of another train (L2) = 260 m
Concept Used:
When trains running in opposite direction crosses each other then, Relative Speed = S1 + S2
Distance = Speed × Time
Calculation:
According to the question,
Relative Speed = (100 + 104) km/h
⇒ 204 km/h
For 'm/s', Relative Speed = 204 × (5/18) m/s
Now, Time = (L1 + L2)/Relative Speed
⇒ (250 + 260)/[204 × (5/18)]
⇒ (510 × 9)/(102 × 5)
⇒ 9 sec.
∴ Both train will cross each other in 9 seconds.