A man can row upstream at 4km/hr and down stream at 11km/hr find mans rate in still water ?
Pick.
A) 4.5km/hr B) 5.5km/hr C) 7.5km/hr D) 6.5km/hr E) 3.5km/hr
given upstream(u) =4km/hr   down stream (v)= 11km/hr rate in still water =1/2(u+v)=1/2(4+11)=7.5km/hr Answer is (7.5km/hr):7.5
<result>C</result>
A man can row upstream at 4km/hr and down stream at 11km/hr find mans rate in still water ?