Question 5 : Suppose the consumer can only purchase two items: hot-dog and burger. Prices of Hotdog and burger are 1 and 2 yuan per unit, respectively. Assume the consumer's income is 20 yuan. Graph the consumer's budget constraint. Note: vertical axis is the hot-dog, and horizontal axis is the burger. Suppose the consumer chooses to have 6 burgers, how many hot-dogs could this consumer purchase at most? Suppose this point is the optimum, please show the indifference curve upon this point