Question 635595


How many gallons of milk containing 4% butterfat must be mixed with 80 gallons of 1% milk to obtain 2% milk?

I'm having trouble figuring out how to set up mixture problems, so please work it out step-by-step with detailed instructions. 


Let amount of 4% butterfat milk to be added be F


Amount of 4% butterfat milk, plus 80 gallons of 1% milk, equals 2% of the sum of the amount of butterfat milk to be added, and 80 gallons.


This statement, in equation form is: .04F + .01(80) = .02(F + 80)


.04F + .8 = .02F + 1.6 ---- Distribute


.04F - .02F = 1.6 - .8 


.02F = .8


F, or amount of 4% butterfat milk to be added = {{{.8/.02}}}, or {{{highlight_green(40)}}} gallons 


Send comments and “thank-yous” to “D” at  MathMadEzy@aol.com