# When Frank and Mark finished milking, they found that they had 900 pounds of milk that was 2% butterfat. How much butterfat did they have to add to raise the butterfat content to 10%?

##### 1 Answer

Jul 3, 2018

The added butterfat weighs

#### Explanation:

The number of pounds of butterfat in the 900 pounds of milk was

Then we can say that there was 982 lbs of not-butterfat.

Assume we add enough butterfat that the mixture has 10% butterfat. Let the total weight of the final mixture be

As a percentage,

Therefore the added butterfat must weigh

I hope this helps,

Steve