Answer:
The answer to your question is:
7.2 ounces of butter
6 ounces of sugar
4.8 ounces of flour
3 eggs
Step-by-step explanation:
Data
Recipe for 15 cupcakes
12 ounces butter
10 ounces sugar
8 ounces flour
5 eggs
Process
Rule of three
             12 ounces of butter ------------------- 15 cupcakes
             x                --------------------  9 cupcakes
                 x = (9 x 12) / 15
                 x = 7.2 ounces of butter
             10 ounces of sugar ------------------- 15 cupcakes
             x                -------------------  9 cupcakes
                x = (9 x 10) / 15
                x = 90 / 15
                x = 6 ounces of sugar
             8 ounces of flour ------------------- 15 cupcakes
             x              -------------------  9 cupcakes
                x = (9 x 8) / 15
                x = 4.8 ounces of flour
                5 eggs ------------------- 15 cupcakes
                x      ------------------- 9 cupcakes
                x = (9 x 5)/ 15
                x = 45/15
                x = 3 eggs
