Question

A sailboat travels 48 miles upstream in 6 hours and return back downstream in 4 hours. What is the speed of the boat in still water?

Answer 1

Let s be the speed of the boat in still water.
Let c be the speed of the current.
s - c = 48/6 = 8
s + c = 48/4 = 12
Adding the two equations, we get:
2s = 20
s = 10
The answer is 10 miles per hour.