Question

4. A river tour boat is going down a stream to a park for lunch and then back up. It is a 60-mile round trip. On

the way to the park, the trip takes 2 hours. The trip on the way back takes 6 hours. Both the boat and water are
moving at a constant rate the whole trip. What would be the speed of the boat in still water?

Answer 1

The speed of the boat in still water is 10 miles / hour

Explanation:

The trip there, and the trip back are the same -- 30 miles

Let the rate of the boat = x

Let the rate of the water = y

30 = 2*(x + y)

30 = 6*(x - y)

Divide the top equation by 2

Divide the bottom equation by 6

15 = x + y

5 = x - y Add the equations together.

20 = 2x Divide by 2

20/2 = x

x = 10