A train which has 420 m long, is running 45 kmph. In what time will it cross a person moving at 9 kmph in same direction ?	Choose the correct choice from the following answers:
A) 56 sec
B) 42 sec
C) 36 sec
D) 29 sec.
E) 19 sec.
Time taken to cross a moving person = length of train/ relative speed   Time taken = 420/((45-9) (5/18)   = 420/ 36*(5/18)   = 420/10= 
<gadget id="calculator">420/10</gadget>
<output>42</output>
42 sec   ANSWER:42 sec
<result>B</result>
A train which has 420 m long, is running 45 kmph. In what time will it cross a person moving at 9 kmph in same direction ?