Three grades of milk are 1 percent, 2 percent and 3 percent fat by volume. If x gallons of the 1 percent grade, y gallons of the 2 percent grade, and z gallons of the 3 percent grade are mixed to give x+y+z gallons of a 1.5 percent grade, what is x in terms of y and z? Select.
A) y + 3z  B) (y +z) / 4  C) 2y + 3z  D) 3y + z  E) 3y + 4.5z
X + 2Y + 3Z = 1.5(X + Y + Z)   X + 2Y + 3Z = 1.5X + 1.5Y + 1.5 Z   y + 3zdd and subtract the common terms,   0.5 X = 0.5Y + 1.5Z   Divide by 0.5,   X = Y + 3 Z   y + 3zNSWER:y + 3z
<result>A</result>
Three grades of milk are 1 percent, 2 percent and 3 percent fat by volume. If x gallons of the 1 percent grade, y gallons of the 2 percent grade, and z gallons of the 3 percent grade are mixed to give x+y+z gallons of a 1.5 percent grade, what is x in terms of y and z?