**Please Show Steps in Excel**

Each coffee table produced by Home Woods nets the firm a profit of $15. Each bookcase yields a $20 profit. Home Woods firm is small and its resources limited. During any given production period (of 1 week), 20 gallons of varnish and 15 lengths of high quality redwood are available. Each coffee table requires approximately 2 gallon of varnish and 1 length of redwood. Each bookcase takes 1 gallon of varnish and 2 lengths of wood. Assume minimum 4 coffee table and 5 bookcases should be produced per week.

Formulate this manufacturing problem and then find the optimal solution.