5. (20 ) Mike enjoys pizzas (P) and burgers (B) and his utility function is u(P, B) = 8P + 5B. (1) If the price of a pizza is $20 and the price of a burger is $10 and Mike has $400 to spend on the two goods. To maximize his utility, how many burgers and pizza should he buy ? (2) How would Mike's consumption change if the price of pizzas fell to $16 and the price of burgers remained at $10? (3) How would Mike's consumption change if the price of pizza fell again to $10 and the price of burgers remained at $10? (4) Write down Mike's demand function for pizza and draw it on a graph. And also draw Mike's price-offer curve. You must label all the necessary numbers on your graphs