Question 308529
cream has approximately 22% of butterfat.how many gallons of cream must be mixed with 2% milk to give 20 gallons of milk containing 4% of butterfat

cream 22% fat quantity x
milk fat 2% quantity (20-x)

Blend 4% quantity = 20

concentration of cream fat + concentration of milk fat = concentration of butter fat

0.22x +0.02(20-x) = 20*0.04

0.22x + 0.4 -0.02x=0.8

0.20x = 0.8 -0.4

0.2x= 0.4
x= 2  gallons of cream