A restaurant owner is currently setting up a new restaurant. For the restroom,

he has three options: paper towels, roller towels and hot air dryers. Dryers

have an initial cost of $ 500 each and monthly service charges of $ 100.

Paper towels cost 5 cent and the number of paper towels used varies

directly with the number of customers. Toweling rolls cost $5 per roll

and will be changed daily. Which option should the owner go for protecting

the environment considering this is going to be a posh restaurant?