A kayaker can paddle 12 mi in 2 h moving with the river current. Paddling at the same pace, the trip back against takes 4 h. Assume that the river current is constant. Find what the kayakers speed would be in still water.
Downstream DATA: distance = 12 miles time = 2 hours rate = 12/2 = 6 mph ---------------- Upstream DATA: distance = 12 miles time = 4 hrs rate = 12/4 = 3 mph ---- Equations: Downstream: b + c = 6 Upstream::: b - c = 3 ------ Add to get: 2b = 9 b = 4.5 mph (speed of the boat in still water.) ----- Solve for "c": b + c = 6 4.5 + c = 6 c = 1.5 mph (speed of the current) The answer is 1.5 mph
