1. Consider the following 12 jobs 4-parallel machines problem: Job J1 J2 J3 J4 J5 J5 J? J3 J9 J10 111 J12 p; (minutes) 12 16 8 10 15 4 3 1? 7' 5 9 2 (1) (10 points) Determine the sequence of jobs on each machine to minimize sum of completion times if the machines are identical. (2) (10 points) Now assume that the four machines have different speed. The speed of machine 1 is v; = 0.25, the speed of machine 2 is V2 = 3 and the speed of machine 3 is v; = 2, and the speed of machine 4 is V4 = 2/3