A business manufactures two parts, X and Y. Machines A and B are needed to make each part. To make part X, machine A is needed for 4 hours and machine B is needed for 2 hours. To make part Y, machine A is needed for 1 hour and machine B is needed for 3 hours. Machine A is available for 40 hours each week and machine B is available for 30 hours. The profit from part X is $500 and the profit from part Y is $600. How many parts of each type should be made to maximize weekly profit?