A kayaker paddles upstream for 1.5 hours, then turns his kayak around and returns to his tent in 1 hour. He travels 3 miles each way. What is the rate of the river's current?
rate * time = distance
The didstance, d , is the same for both legs of the trip =3
c = current
p = paddle speed still water
(p-c) * 1.5 hr = 3mi = 1.5 p - 1.5 c = 3
(p+c) 1 hr = 3mi = p + c = 3 Multiply by 1.5 = 1.5 p + 1.5 c = 4.5
Add red equations together 3p =7.5 p = 2.5 m/hr (....and c = .5 m/hr)