The speed of the current in a river is 6 mph. A ferry operator who works that part of the river is looking to buy a new boat for his business. Every day, his route takes him 22.5 miles against the current and back to his dock, and he needs to make this trip in a total of 9 hours. He has a boat in mind, but he can only test it on a lake where there is no current. How fast must the boat go on the lake in order for it to serve the ferry operator’s needs?

Question

anonymous · Answer

@Compassionate @tkhunny @timo86m help?

anonymous · Answer

22.5/(v - 6) + 22.5(v+6) = 9

solve for v

anonymous · Answer

v=9 am i right?