Suppose that you currently own a clothes dryer that costs $ 20 per month to operate. A new efficient dryer costs $ 310 and has an estimated operating...

Suppose that you currently own a clothes dryer that costs ​$20 per month to operate. A new efficient dryer costs ​$310 and has an estimated operating cost of

​$15 per month. How long will it take for the new dryer to pay for​ itself?

The clothes dryer will pay for itself in ______ months.