A company would like to determine the best production schedule using a manufacturing process with four machines: W, X, Y, and Z. Each machine can be used for 2400 minutes per week.

The weekly demands and the processing time on machines are shown below. Product A, 150 units/week, 6, 10, 6, 0 minutes; Product B, 90 units/week, 0, 9, 7, 8 minutes; Product C, 120 units/week, 8, 8, 7, 5 minutes; Product D, 130 units/week, 7, 0, 5, 8 minutes.

The above table shows that product A needs 6 minutes on machine W, 10 minutes on machine X, 6 minutes on machine Y, and 0 minute on machine Z.

The production manager has decided to manufacture product D first, product A second, product B third, and product C last.

Determine how many units can be manufactured for each product given the manager's decision.

Show brief calculation and explanation.