Answer:
Fiona should use 1 cup of butter
Explanation:
If the ratio of flour to butter is 24:8, it means that for every 24 parts of flour, there are 8 parts of butter. We can simplify this ratio by dividing both the numerator and denominator by the greatest common factor, which is 8 in this case:
24/8 : 8/8
3 : 1
This means that for every 3 parts of flour, there is 1 part of butter.
If Fiona uses 3 cups of flour, then the amount of butter she needs can be found by multiplying the amount of flour by the ratio of butter to flour:
3 cups of flour x 1/3 cups of butter per cup of flour = 1 cup of butter
Therefore, Fiona should use 1 cup of butter.