Answer:
2.5 cups of milk
Step-by-step explanation:
Given that,
A cake recipe calls for 1.5 cups of milk and 3 cups of flower.
Seth made a mistake and used 5 cups of flour.
We need to find number of cups of milk he use to keep the proportions correct. Let he used x cups of milk.
[tex]\dfrac{1.5}{3}=\dfrac{x}{5}\\\\x=\dfrac{1.5\times 5}{3}\\\\x=2.5[/tex]
Hence, he should use 2.5 cups of milk.