Hi all,

Couldn't figure this one out. Would appreciate a brief explanation. thanks!

Q) 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?

1) y + 3z

2) (y + z) / 4

3) 2y + 3z

4) 3y + z

5) 3y + 4.5z