Answer: 1/4
Explanation:
Let the volume of mixture (6%fat) in cup is 100cc
x cc be the volume of cream (18% fat) in the mixture.
∴
(100−x) cc be the volume of milk (2% fat) in the mixture.
x * 0.18+(100−x) * 0.02=100
⋅0.06 or 0.18x − 0.02x = 6−2 or 0.16x
= 4 or x=25 cc = 25%