A man can row upstream 11 kmph and downstream 17 kmph. Find the rate of the stream.

 a) 3 km/hr
 b) 6.5 km/hr
 c) 7 km/hr
 d) 13 km/hr

3 km/hr. Solution If a is rate downstream and b is rate upstream Rate of current = 1/2(a-b) ==> (17 - 11)/2 = 3