The amount of milk containing 6% butterfat and 1% butterfat are 260 gallons and 65 gallons respectively.
Step-by-step explanation
Suppose, the amount of milk containing 6% butterfat is
gallons
As the amount of mixture of milk should be 325 gallons, so the amount of milk containing 1% butterfat will be:
gallons
Given that, the mixture of milk is containing 5% butterfat. So, the equation will be....

So, the amount of milk containing 6% butterfat is 260 gallons and the amount of milk containing 1% butterfat is (325-260) gallons = 65 gallons.