Carcass wrote:
The protein-fat ratio for the foods here equals the ratio of “% of protein” to “% of fat.” The ratios for foods A, B and C are, respectively, 10/30 = 1/3, 20/20 = 1/1, 30/35 = 6/7.
In all of these, protein is less than fat.
Choice (C): Now, considering the combination in choice (C), food A to B ratio is 60 : 40. Hence, choose 6 gm of food A and 4 gm of food B, so that foods are in this ratio. Food A has 10% protein and 30% fat. 10% of 6 gm is 0.6 and 30% of 6 is 1.8. Food B has 20% protein and 10% fat. 20% of 4 gm is 0.8 and 10% of 4 is 0.4. The net sum: Protein = 0.6 (from A) + 0.8 (from B) = 1.4. The net sum: Fat = 1.8 (from A) + 0.4 (from B) = 2.2.
The food has less protein than Fat. Reject the choice.
Choice (D): Now, considering the combination in choice (D), food B to C ratio is 60 : 40. Hence, choose 6 gm of food B and 4 gm of food C, so that foods are in this ratio. Food B has 20% protein and 10% fat. 20% of 6 gm is 1.2 and 10% of 6 is 0.6. Food C has 30% protein and 35% fat. 30% of 4 gm is 1.2 and 35% of 4 is 1.4. The net sum: Protein = 1.2 (from B) + 1.2 (from C) = 2.4. The net sum: Fat = 0.6 (from B) + 1.4 (from C) = 2.0. The food has more protein than Fat. This is a correct choice.
Choice (E): Both the foods A and C have higher fat percentage than protein percentage. So, any combination of the food will not result in a higher protein than fat. Reject the choice. The answer is (D).
For food B, the percent of fat is 10. Thus the ratio of protein to fat is 20/10 = 2 > 1, hence answer B works as well. Am I missing something?