Question

A dairy needs 364 gallons of milk containing 6% butterfat. How many gallons each of milk containing 7% butterfat and milk containing 3% butterfat must be used to obtain the desired 364 gallons?

Answer 1

Explanation:

Let x be gallons of 7%

Let y be gallons of 3%

364 = x + y

y = 364 - x

364(0.06) = x(0.07) + y(0.03)

364(6) = x(7) + y(3)

364(6) = 7x + 3y

364(6) = 7x + 3(364 - x)

364(6 - 3) = 7x - 3x

364(3) = 4x

x = 273

y = 364 - 273 = 91

273 gallons of 7%

91 gallons of 3%