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**symmetry** A motorboat heads upstream on a river that has a current of 3 mph. The trip upstream takes 5 hours, while the return trip takes 2.5 hours. What is the speed of the motorboat?

Assume that the motorboat keeps a constant speed relative to the water.

NOTE: What is the meaning of the assumption made above?

I've seen upstream and downstream questions before. However, I always get confused when it comes to setting up the right table or chart that leads to the correct equation that leads to the answer.