SOLUTION: A motorboat heads upstream on a river that has a current of 3 miles per hour.The trip upstream takes 5 hours,and the return trip takes 2.5 hours.What is the speed of the motorboat?

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Question 1207749: A motorboat heads upstream on a river that has a current of 3 miles per hour.The trip upstream takes 5 hours,and the return trip takes 2.5 hours.What is the speed of the motorboat? (Assume that the motorboat maintains a constant speed relative to the water.)

Let me see.

I will denote the speed of the motorboat as “b” and the speed of the current as “c”. When going upstream, since it is against the current, I say this:
Speed = b - c
When going downstream (with the current), I say this: Speed = b + c.
I know that distance = speed × time.
For the upstream trip: 5(b - 3) miles.

For downstream trip: 2.5(b + 3) miles.

Since both distances are equal (the boat travels to a point and then returns from there), I can set up an equation:
5(b - 3) = 2.5(b + 3)

Is this correct?
Answer by josgarithmetic(39620) (Show Source):
You can put this solution on YOUR website!
The setup equation IS correct.
Your analysis of the description is correct.