A salad is any combination of the following ingredients: (1) tomato, (2) lettuce, (3) spinach, (4) carrot, and (5) oil. Each salad must contain: (A) at least 15 grams of protein, (B) at least 2 and at most 6 grams of fat, (C) at least 4 grams of carbohydrates, (D) at most 100 milligrams of sodium. Furthermore, (E) you do not want your salad to be more than 50% greens by mass. The nutritional contents of these ingredients (per 100 grams) are: ingredient energy protein fat carbohydrate sodium (kcal) (grams) (grams) (grams) (milligrams) tomato 21 0.85 0.33 4.64 9.00 lettuce 16 1.62 0.20 2.37 8.00 spinach 371 12.78 1.58 74.69 7.00 carrot 346 8.39 1.39 80.70 508.20 oil 884 0.00 100.00 0.00 0.00 Define and solve a linear program which makes the salad with the fewest calories under the nutritional constraints.