14. A special food for patients is to be developed from two foods: “Food M” and “Food N”. The new food is designed so that it contains exactly 31mg of vitamin A, 33 mg of vitamin B, and 29 mg of vitamin C. Each kg of food M contains 3 mg of vitamin A, 5 mg of vitamin B and 1 mg of vitamin C. On the other hand, each kg of food N contains 2 mg of vitamin A, 1 mg of vitamin B and 3 mg of vitamin C. How many kg of each food should be used in the mixture in order to meet the above requirement? USE a) Inverse method b) Gaussian method