Question

A dairy farmer wants to make an 8% butterfat mixture. How many pounds of milk containing 3% butterfat must she add to 100 pound of cream containing 20% butterfat? Please help!

Answer 1

x is the # of pounds of milk
(.03x + .2*100)/(100+x)=.08

Answer 2

Why is it divided by (100+x)?

Answer 3

odd way of looking at it but i guess it works

Answer 4

the 100 pounds of cream containing 20% butterfat has 20 pounds of butterfat. if i you add x pounds of 3% butterfat milk it will then contain
\[20+.03x\] butterfat. you will have \[100+x\] pounds of milk which you want to be 8% butterfat, so set
\[20+.03x=.08(100+x)\] and solve for x