A boat travels upstream for 240 miles in 4 hours and returns in 3 hours traveling downstream in a local stream of water. What is the rate of the boat in still water and the rate of the current?

Answer 1

240 miles in 4 hours is 240/4 = 60 mph upstream speed

240 miles in 3 hours is 240/3 = 80 mph downstream speed

s + r = 80

s - r = 60

2s = 140

s = 140/2 = 70 mph = boat speed in still water

r = 80-70 = 10 mph = speed of the current