a2zinterviews

16.	A man in a train notices that he can count 21 telephone posts in one minute. If they are known to be 50 metres apart, then at what speed is the train travelling?
	A.  55 km/hr
	B.  57 km/hr
	C.  60 km/hr
	D.  63 km/hr

Solution

Number of gaps between 21 telephone posts = 20. Distance travelled in 1 minute = (50 x 20)m = 1000m = 1 km. Speed of the train travelling is = 60 km/hr.

17.	A man walking at the rate of 5 km/hr crosses a bridge in 15 minutes. The length of the bridge (in metres) is
	A.  600
	B.  750n
	C.  1000
	D.  1250

Solution

speed = (5x5/18)m/sec = 25/18 m/sec. Distance covered in 15 minutes = (25/18 x 15 x 60)m = 1250 m.