To determine the number of butter that is needed in the problem, we need an equation that would relate the three variables since these affects the number of cups of ingredients. We are given the ratio of the three ingredients which is 5 cups of flour per 2 cups of sugar per 1 cup of butter. From this we can set up the equation as:
total number of cups = 5c + 2c +1c
However, it was said that the number of cups of sugar has to be lessened by 1 cup so the equation would change accordingly as
total number of cups = 5c + (2c -1) +c
We calculate as follows:
27 = 5c + (2c -1) +c
27 = 5c + 2c - 1 + c
28 = 8c
c = 7/2
Therefore, Miguel needs 7/2 or 3 and 1/2 cups of butter.
