A Moving to another question will save this response. > Question 19 1 points Save Answer Brenda can sell 10 posters for $100 each, 20 posters for $90 each, 30 posters for $80 each, 40 posters for $70 each, and 50 posters for $60 each. Her marginal cost of production is constant at $60 for each additional unit (or poster) produced. If she behaves like a perfectly competitive producer, what is the number of posters she will sell? O a. 10 O b. 30 O c. 40 O d. 50 A Moving to another question will save this response. >A Moving to another question will save this response. > Question 20 1 points Save Answer What is true about the Marginal Cost? O a. It is calculated as the change in Total Cost divided by change in Total Quantity O b. It is calculated as the change in Total Variable Cost divided by the change in Total Quantity O c. Both a) and b) are true O d. Neither a) nor b) is true A Moving to another question will save this response. >li> A Moving to another question will save this response. > Question 21 1 points Save Answer Assume that a producer pays $600 in fixed costs. For producing 50 units of their product, they pay $200 in variable costs, and for producing 60 units, they pay $500 in variable costs. As they increase production from 50 units to 60 units, which of the following is true? O a. Average Total Cost increases because spreading effect is greater than diminishing returns effect O b. Average Total Cost increases because diminishing returns effect is greater than spreading effect O c. Average Total Cost decreases because spreading effect is greater than diminishing returns effect O d. Average Total Cost decreases because diminishing returns effect is greater than spreading effect .) A Moving to another question will save this response. &gt