Final answer:
To determine the amount of flour needed for the recipe, subtract the 1 cup of sugar from the total 3 cups required. Hence, 2 cups of flour is needed.
Step-by-step explanation:
The question is asking how much flour is required when a recipe calls for a total of 3 cups of flour and sugar combined, and we know that 1 cup of that mixture is sugar. To solve this, we subtract the amount of sugar from the total to find the amount of flour. If the recipe requires 1 cup of sugar, here's how you calculate the flour needed:
3 cups (total) - 1 cup (sugar) = 2 cups (flour)
Therefore, the recipe requires 2 cups of flour.