Sketching the Graph from Given Information

"National Supermarkets is selling ground beef this week at the following prices: 2.00/lb (packages less than three pounds) 1.00/lb (packages of three pounds or more) a. Find the function that describes, the cost if a package, as a function of X, the number of pounds of ground beef in the package. b. Sketch the graph of this function c. How much money does a shopper save if he buys one 3 pound package instead of three 1 pound packages. Where does the savings appear on your graph? "