A motorboat travels 246 kilometers in 6 hours going upstream. It travels 330 kilometers going downstream in the same amount of time. What is the rate of the boat in still water and what is the rate of the current?

Total rental cost is:

y = Bx + M

where x is number of additional hours, y is total cost, M is fixed fee, and B are  is amount that is charged per hour.

Step-by-step explanation:

Let amount of flat fee = M

let hourly rate = B

Total rental cost = ?

As given the store charges a flat fee plus an hourly rate:

                                      ⇒    y = Bx + M

where x is number of additional hours, y is total cost, M is fixed fee, and B are  is amount that is charged per hour.