Formulate and solve an integer programming model

Harry and Melissa Jacobson produce handcrafted furniture in a workshop on their farm. They have obtained a load of 600 board feet of birch from a neighbour and are preparation to produce round kitchen tables and ladder-back chairs during the next 3 months.

Each table will require 30 hours of labour, each chair will require 18 hours, and between them they have a total of 480 hours of labour available. A table requires 40 board feet of wood to make, and a chair requires 15 board feet. A table earns the couple $575 in profit, and a chair earns $120 in profit. Most people who buy a table also want four chairs to go with it, so for every table that is produced, at least four chairs must also be made, although additional chairs can also be sold separately. Formulate and resolve an integer programming model to determine the number of tables and chairs the Jacobson's should make to maximize profit.