A man can row upstream at 4kmph and downstream at 10 kmph. The speed of the stream is Select:	A) 2.5 km/hr	B) 4.2 km/hr	C) 3 km/hr	D) 10.5 km/hr	E) None
Sol.   Speed of stream = 1/2(10 -4) kmph = 3 kmph.   Answer 3 km/hr
<result>C</result>
A man can row upstream at 4kmph and downstream at 10 kmph. The speed of the stream is