Each coffee table produced by John Alessi Designers nets the firm a profit of $$9.$ Each bookcase yields a $$12$ profit. Alessi's firm is small and its resources limited$.$ During any given production period $($of one week$),10$ gallons of varnish and $12$ lengths of high$-$quality redwood are available. Each coffee table requires approximately $1$ gallon of varnish and $1$ length of redwood. Each bookcase takes $1$ gallon of varnish and $2$ lengths of wood.