Answer:
0.75 cups of flour
Explanation:
The recipe
1.5 cups flour - 1 cup sugar
Then
0.5 cups of sugar - ? cups of flour
You divide 1 cup into 2 to get 0.5 cups of sugar, which means the recipe is divided by half to bake the muffins. So,
1.5 divided by 2 gives you 0.75 cups of flour
(If my explanation was wrong, please correct me, Thanks :)