Optimization problem?

Question

Each machine in a certain factory can produce 50 units per hour. The setup cost is $80 per machine, and the operating cost is $5 per hour. How many machines should be used to produce 8000 units at the least possible cost?

thanks

Answer 1

Something may be wrong with that question.

The answer as it is written is to set up a single machine, and keep producing until you are done.

The cost function is simply 80 * (number of machines) + 0.1 * (number of units), and the number of units is fixed.