Question

How much of 2% milk and 7% milk do I mix to make 40 quarts of 5% milk?

Answer 1

40 quarts of 5% milk has 40 *5% quarts ( 2 quarts) of 100% milk.

if we need x quarts of 2% milk and y quarts of 7% milk , then we have

2% x + 7% y =2
x+y=40

get x=16 and y =24.

so we need 16 quarts of 2% milk and 24 quarts of 7% milk~