For a blueberry recipe you need 3/4 cups of sugar, 1/8 cup of butter and 3/8 of blueberries. How many cups of blueberries are needed for 1/3 of a cup of sugar?
We can solve this with a proportion
( 3/8) / (3/4) = x / (1/3) where x is what we need ....cross-multiply
(1/3) (3/8) = (3/4) x
(3 /24) = (3/4)x
(1/8) = (3/4)x multiply both sides by 4/3
(4/3) (1/8) = x = 4 / 24 = 1 / 6 cups of blueberries