Answer: ($2,000)
Explanation:
With S3 as the supply curve, the equilibrium price is $10.
With this being a Perfectly competitive market, the profit maximising quantity will be where Price which is the same as Marginal Revenue equals Marginal cost.
That quantity is 200 gallons a week.
At this same level, the Average Total Costs are $20.
Profit (Loss) = (Price - ATC) * Quantity
= (10 - 20) * 200
= ($2,000)
