Final answer:
Colin should use 3/8 cup of brown sugar for a small batch with 1 cup of flour. This is determined by setting up a proportion based on the recipe's ratio and solving for the unknown amount of sugar.
Step-by-step explanation:
To determine how much brown sugar Colin should use for 1 cup of flour, we need to set up a proportion based on the original recipe. The original ratio is 3/4 cup of brown sugar to 2 cups of flour. We want to find out how much brown sugar is needed for 1 cup of flour.
The proportion will be:
(3/4 cup brown sugar) / (2 cups flour) = (x cup brown sugar) / (1 cup flour)
To solve, you multiply both sides by 1 cup (the amount of flour you're using) to isolate x, which represents the needed amount of brown sugar.
(3/4) * (1/2) = x
3/8 = x
Therefore, Colin should use 3/8 cup of brown sugar for the small batch with 1 cup of flour, which corresponds to option A.