Can you please tell me how to calculate the contribution margin of good a , b and c respectively with numerical workings , thank you very much ??

_| ABC produces three goods: Good A, Good B and Good C. The contribution per unit of the respective products is as follows: Good A Good B Good C Contribution per unit 840 640 1240 To produce these products, it requires two steps which is process ready and process mix. The processing time requirement for each respective product are listed below. Good A Good B Good C Process Ready 50 100 80 Process Mix 70 80 110 The monthly processing time of Process Ready and Process Mix is limited to 100,000 hours and 160,000 hours respectively. The sales of Product A are limited to 1800 units per month due to regulatory restrictions. Company's objective is contribution maximisation