Question

A Train of length 250 m crosses a platform 3 times of its length in 50 seconds. Train B having the length of 300 m at the speed of 54 kmph going in same direction completely overtaken by train A in how much time?
1. 150 sec
2. 110 sec
3. 120 sec
4. 100 sec
5. 300 sec

Answer 1

Correct Answer - Option 2 : 110 sec

GIVEN:

Length of Train = 250 meter.

Length of Platform : Length of Train = 3x : 1x

Length of Platform = 750 meter.

Speed of train B = 54 kmph or 15 m/s

ASSUMPTION:

Let the time taken to cross each other = T seconds.

Let speed of Train A = (S) m/s.

FORMULA USED:

Speed of Train = length of Train / Time taken      ----(1)

CALCULATION:

From eq(1)

⇒ S = (750 + 250) / 50

⇒ S = 20 m/s or 72 kmph

When Train A and B cross each other.

⇒ (v - v_B) = (250 + 300)/T

⇒ T = (250 + 300)/5

⇒ Time = 110 seconds.