Question

A canoeist paddled down a river a distance of 2 miles in 45 minutes. Paddling up-stream on his return, it took him 90 minutes. Find the rate of the canoe in still water.

Answer 1

Speed of canoe in still water we will denote it CS and water itself has a speed we denote it WS. Downstream will be (CS + WS)*45 = 2, Upstream will be (CS - WS)*90 = 2. Solve the system you will find canoe speed in still water and the water speed as well. 90CS = 90WS +2, CS = WS+ 1/45 put it in the first function 90WS +1 = 2, WS = 1/90 miles per minute, CS =1/30 miles per minute.