The length of train A is x+10 meters and length of train B is x+20 meters…

2025

The length of train A is x+10 meters and length of train B is x+20 meters respectively. Both trains cross each other is 11/2 seconds and speed of train A is 90 km/hr. The speed of train B is 40% more than that of train A, then find the time taken by the train B to cross a 110 meters long platform (in seconds)?

  1. A.

    10

  2. B.

    12

  3. C.

    8

  4. D.

    6

  5. E.

    16

Attempted by 3 students.

Show answer & explanation

Correct answer: C

Train A speed = 90 km/hr = 25 m/s. Train B speed is 40% more, so it is 126 km/hr = 35 m/s.

They cross each other in 5.5 s with relative speed 60 m/s, so combined length = 60 x 5.5 = 330 m.

Lengths are x + 10 and x + 20, so 2x + 30 = 330 and x = 150. Train B length = 170 m.

Time for B to cross a 110 m platform = (170 + 110)/35 = 8 s.

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