3. (a) If the demand function of a good is given by: P = 40-2Q (i) Find the price when Q-5, and then calculate the total revenue at that price. [2] (ii) If fixed costs are 60 and variable costs are 4 per unit, find the total cost when Q=5. [3] (iii) Use your answers in parts (i) and (ii) to calculate the corresponding profit. [2] (b) (i) Show that the following function is homogenous and state its degree of homogeneity. Q K + L K+L [3] (ii) Does this production function display increasing, decreasing or constant returns to scale? [3] (iii) Find the output when K-15, and when L=25. [2]