Two trains A and B are 100 m and 150 m long and are moving at one another at 54 Km/hr and 36 Km/hr respectively. Arun is sitting on coach B1 of train A. Calculate the time taken by Arun to completely cross Train B.
Choose the correct choice from the following answers:	A) 10 s	B) 6 s	C) 4 s	D) 8 s	E) 12 s
DETAILED SOLUTION   Speed of A = 54∗1000/60∗60 = 15 m/s   Speed of B = 36∗1000/60∗60 = 10 m/s   Relative speed = S1 + S2 = 15 + 10 m/s = 25 m/s   The length that needs to be crossed = length of train B = 150 m. Therefore time taken = 150/25= 
<gadget id="calculator">150/25</gadget>
<output>6</output>
6s.   What is the time taken for trains to completely cross each other? The length that needs to be crossed= 100 + 150= 
<gadget id="calculator">100 + 150</gadget>
<output>250</output>
250 m. Time taken= 250/25= 
<gadget id="calculator">250/25</gadget>
<output>10</output>
10 s.   CORRECT ANSWER 6 s.
<result>B</result>
Two trains A and B are 100 m and 150 m long and are moving at one another at 54 Km/hr and 36 Km/hr respectively. Arun is sitting on coach B1 of train A. Calculate the time taken by Arun to completely cross Train B.