(c) A company's profit function is given by (q) = - q38 + 18q2 -60q -50, where q is the quantity supplied. If the demand for the company's product for a price p is given by the equation p + q=25 find its cost function. For what values of q is the profit function economically meaningful? (4 marks) li. Find and classify the stationary points of at(q). (4 marks)Q3: (a) Suppose that you buy a computer for 16000 pounds and its value depreciates continuously at the rate of 20% per year. i . What is its value after four years? (3 marks) ii. After how many years the computer's value will be 4000 pounds? (3 marks) (b) The second term in an arithmetic series is three and the sum of the first ten terms is 65. Find the first term and the common difference. (3 marks) (5 marks) (c) You win a competition and can choose one of the following prizes: $30,000 now. (11) $20,000 now and another $20,000 in two years' time. (iii) $10,000 at the end of each year for the next four years. Given access to a bank account that pays 5% interest per year annually compounded, find the present value of each prize. Which prize should you choose? Briefly justify your choice. (7 marks)