Dear Tutor, please help in explaining the following questions: a. Explain the essence of the economies of scale and opportunity cost. Give two actual examples of each concept.

b. By using formula below, explain the concept of economies of scope: TC(Qx, Qy) - TC (0, Qy) < TC(Qx, 0) - TC(0, 0)

c. Show the difference between sunk cost and fixed cost with one concrete example.

Thank you.