Happy Bubble Tea, Inc., has been granted a restrictive licensing and operates a chain of bubble tea stalls in Country A. Happy Bubble Tea, Inc. has its inverse demand function of P = 40 - 0.004Q, with both its marginal cost and average total cost of $16 per cup under the existing operation. (a) With the aid of a diagram, calculate the profit-maximising level of output and price and profit. (7 marks)