A jogger running at 9 kmph alongside a railway track is 240 meters ahead of the engine of a 120 meter long train running at 45 kmph in the same direction. In how much time will the train pass the jogger ?

A.  3.6 sec   
B.   18 sec
C.  36 sec   
D.  72 sec
Answer: C

Explanation:

Speed of train relative to jogger = (45 - 9) km/hr
                                                = 36 km/hr
                                                = (36 x 5/18) m/sec
                                                = 10 m/sec
Distance covered    = (240+120) m
                              = 360 m
Time taken    = (360 / 10)sec
                     = 36 sec.