You are stenciling wooden boxes to sell at a fair. It takes you 2 hours to stencil a small box and 3 hours to stencil a large box. You make a profit of $10 for a small box and $20 for a large box. If you have no more than
30 hours available to stencil and want at least 12 boxes to sell, how many of each size box should you stencil
to maximize profit? find the profit function and constraints