In this case, we'll have to carry out several steps to find the solution.
Step 01:
12 cupcakes:
3 1/2 cups of flour
3/4 cups of sugar
1 cup of sugar:
cups of flour = ?
Step 02:
3 1/2 cups of flour = 3 + 0.5 = 3.5
3/4 cups of sugar = 0.75
cups of flour = 4.67
The answer is:
It needed 4.67 cups of flour