A recipe for 4 servings requires 2 cups of flour. If the recipe is first scaled to make 10 servings, and then that amount is doubled for a…

First find the flour per serving: 2 cups for 4 servings is $\frac{2}{4} = 0.5$ cup per serving. For 10 servings, that is $0.5 \times 10 = 5$ cups. The amount is then doubled for the party, so $5 \times 2 = 10$ cups, choice A. Choice B (5) stops after the first scaling and forgets to double. Choice C (20) doubles the recipe twice or scales 4 servings to 10 using the wrong factor. Choice D (8) comes from multiplying 2 cups by 4, mixing up servings and cups and skipping the scaling to 10 servings. Both steps are needed.