we know that
Recipe ------> 1 1/2 cups of fluor for the muffins and 1/4 cups of fluor for the topping
so
For 1/2 recipe
Divide by 2 the original cups of fluor of the recipe
therefore
cups of fluor for the muffins
(1 1/2):2
but first convert mixed number to an improper fraction
1 1/2=1+1/2=3/2
substitute
(3/2):2=3/4 cups of fluor for the muffins
cups of fluor for the topping
1/4:2=1/8 cups of fluor for the topping
Total cups of fluor
(3/4)+(1/8)=7/8 cups of fluor