How many cu m of butterfat must be removed from 500 cu m of milk containing 10% butterfat to reduce its conten

Question

How many cu m of butterfat must be removed from 500 cu m of milk containing 10% butterfat to reduce its content to 4% butterfat?

Answer 1

Original volume is 50 butterfat and 450 milk. For it to be 4%:

450/(450+x) = 1 - 0.04, where x is the remaining butterfat
450 = 432 - 0.96x
0.96x = 18
x = 18.75

Remove 31.25 cu m butterfat.