Formulate, but do not solve, the following linear programming problem. Suppose a person decides to make rice and soybeans part of his staple diet. The object is to design a lowest-cost diet that provides certain minimum levels of protein, calories, and Vitamin B 12 (riboflavin). Suppose that one cup of uncooked rice costs 38 cents and contains 15 grams of protein, 810 calories, and1/9 milligram of riboflavin. On the other hand, one cup of uncooked soybeans costs 45 cents and contains 22.5 grams of protein, 270 calories, and 1/3 milligram of riboflavin. Suppose that the minimum daily requirements are 90 grams of protein, 1620 calories, and 1 milligram of riboflavin. Design the lowest-cost diet meeting these specifications.