Answer:
9 mph
Step-by-step explanation:
-Let x be the speed of the boat upstream.
-Since the time upstream and downstream is equal, we will equate their time functions to solve for x:
-Speed upstream=x-8
-Speed downstream=x+8
#We then equate as follows:
[tex]Time =\frac{Distance}{Speed}\\\\Time_1=Time_2\\\\\\\frac{10}{x-8}=\frac{20}{x+8}\\\\10(x+8)=20(x-8)\\\\10x+80=20x-160\\\\10x=240\\\\x=24\ mph[/tex]
Hence, the speed of the boat in still water is 9 mph
