Posted by ashley on Sunday, September 16, 2012 at 8:41pm.
A kayak moves at a rate of 12 mph in still water. If the rivers current flows at a rate of 5mph how long does it take the boat to travel 23 miles upstream?

math  Reiny, Sunday, September 16, 2012 at 8:43pm
so the effective rate = 125 or 7 mph
time = 23/7 = 3.2857 hrs
= 3 hrs and appr 17 minutes