Trains 21Q

21.30. A train 110 m long passes a man, running at 6 kmph in the direction opposite to that of the train, in 6 seconds The speed of the train is

             A.  54 km/hr         B.  60 km/hr

             C.  66 km/hr         D.  72 km/hr

Answer:B

Speed of the train relative to man     = (110 / 6 ) m/sec

= (110 / 6 x 18 /5) km/hr

= 66 km/hr

speed of the train be x kmph.

Relative Speed       =(x + 6 ) kmph.

= x + 6 = 66

x = 60.