please help me with this homework

thank

A dietician wishes to mix together two kinds of food X and Y in such a way that the mixture contains at least 10 units of vitamin A,12 units of vitamin B and 8 units of vitamin C. The vitamin contents of one kg food is given below: One kg of food costs OMR 16 and one kg of food Y costs OMR 20. Find the least cost of the mixture which will produce the required diet