Answer:
The 20 quarts are used for 6% butterfat milk and 10 quarts are used for 3% butterfat milk .
Step-by-step explanation:
As given
6% butterfat milk and 3% butterfat milk should be mixed to yield 30 quarts of 5% butterfat milk .
Let us assume that x quarts are used for 6% butterfat milk .
Than (30 - x) quarts are used for 3% butterfat milk .
6% is written in the decimal form
= 0.06
3% is written in the decimal form
= 0.03
5% is written in the decimal form
= 0.05
Than the equation becomes
0.06 × x + (30 - x) × 0.03 = 30 × 0.05
0.06x + 0.9 - 0.03x = 1.5
0.06x - 0.03x = 1.5 - 0.9
0.03x = 0.6
x = 20 quarts for 6% butterfat milk .
(30 - x ) = (30 - 20) = 10 quarts for 3% butterfat milk .
Than 20 quarts are used for 6% butterfat milk and 10 quarts are used for 3% butterfat milk .