A dairy needs 230 gallons of milk containing 6% butterfat. How many gallons each of milk containing 8% butterfat and milk containing 3% butterfat must be used to obtain the desired 230 gallons?

138 gallons - milk containing 8% butterfat , 92 gallons -  milk containing 3% butterfat

Step-by-step explanation:

Firstly, find the quantity of butterfat in  the dairy needs of milk

230/100*6= 2.3*6=13.8 gallons of butterflat

1) Consider gallons each of milk containing 8% butterfat and milk containing 3%, suppose we need x gallons of milk containing 8 percents butterfat, then we need 230-x gallons of milk containing 3percent butterfat.

Then the quantity of the butterfat in the 8percents fat milk is x/100*8= 0.08x

the quantity of the butterfat in the 3percents fat milk is (230-x)/100*3=

=0.03 (230-x) = 6.9-0.03x The amount of butterfat of the both milk containing 8% butterfat and milk containing 3%is equal to 13.8 gallons

Then 0.08x+6.9-0.03x=13.8

0.05x=6.9

x=6.9/0.05= 138 -milk 8 percents

230-x= 230-138= 92