Taking into account the rule of three, 12 cups of flour should be used if 48 cups of sugar are used.
Rule of three
The rule of three is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them.
That is, what is intended with it is to find the fourth term of a proportion knowing the other three.
If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other), the direct rule of three must be applied.
To solve a direct rule of three, the following formula must be followed, being a, b and c known data and x the variable to be calculated:
a ⇒ b
c ⇒ x
Being x= (c×b)÷a
Cups of flour
For a given recipe, 3 cups of flour are mixed with 12 cups of sugar. Then:
12 cups of sugar⇒ 3 cups of flour
48 cups of sugar⇒ x
So:
x= (48 cups of sugar×3 cups of flour)÷12 cups of sugar
Solving:
x= 12 cups of flour
In summary, 12 cups of flour should be used if 48 cups of sugar are used.