Debbie traveled by boat 5 miles upstream to fish in her favorite spot. Because of the 4-mph current, it took her 20 minutes longer to get there than to return. How fast will her boat go in still water?
When it travels upstream its speed= mph
Time taken to go upstream= h
Speed in downstream = mph
Time taken to go downstream or time taken to return back= h
And 20 min hrs
But according to question...
Solve it and you will get the answer