Suppose you make and sell doughnuts. You sold about 200 doughnuts a week when the price of each doughnut was 5 dollars You discovered that when you increased the price of each doughnut by 5 dollars, your sales decreased by about 50 doughnuts per week. (a) What is the demand function, assuming that it is linear? (b) If it costs you 3 dollars to make each doughnut, what selling price would give you maximum profit weekly