Beth's Lawn Mowing Service is a small business that acts like a price taker. The prevailing market price of lawn mowing is $20 per acre. When Beth was using the family mower for free, she has other costs each week are given by:

• Total Cost = 0.1q² + 10q + 50
• Marginal Cost = 0.2q + 10

Where q = the number of acres Beth chooses to mow in a week. Now assume that in addition to the above costs, Beth must pay her greedy Dad $100 per week to use the family mower. Find the profit maximizing number of lawns to cut in the short-run given that her Dad is now charging her $100 per week to use the family mower.