Correct Answer - Option 1 : 130 m
Given:
Length of 1st train is 220m
Speed of 1st train is 110 km/h
Speed of 2nd train is 70 km/h
Formula Used:
Relative speed of train in opposite direction = S1 + S2
Time = Distance/Speed
Calculation:
Let the length of 2nd train be x
Relative speed of train = 110 + 70 = 180 × 5/18 = 50 m/sec
According to the question;
Time = (220 + x)/50
⇒ 7 = (220 + x)/50
⇒ 350 = 220 + x
⇒ x = 130 m
∴ The length of other train is 130 m