A dairy needs 258 gallons of milk containing 7% butterfat. How many gallons each of milk containing 8% butterfat and milk containing 2% 2 % butterfat must be used to obtain the desired 258 258 gallons?

8.75

how-to:

first, we need to find what we have to work with.

since i know that we have 7 (years) and 0.8 (inches), we can use these to solve and find the equation!

secondly, what you want to do, is see that we need to know how much growth out of the 0.8 inches he got in only 1 year, instead of 7 years.

let's try to divide.

7 ÷ 0.8 = 8.75

7 9/10 as an improper fractions is 79/10.

hope it : )