21) The short-run cost function of a company is given by the equation TC = 400 + 65q, where TC is the total cost and q is the total quantity of output.

a. What is the company's fixed cost?

b. If the company produced 100 units of goods, what would be its average variable cost?

c. What would be its marginal cost of production?

d. If the company produced 100 units of goods, what would be its average fixed cost?

e. Suppose the company borrows money and expands its factory. Its fixed cost rises by 50, but its variable cost falls to 45 per units. Write the new cost equation.

please help thank you