Three grades of milk are 1%, 2% 3% fat by volume. If x gallons of the 1% , y gallons of 2% grade & z gallons of 3% grade mixed to give x+y+z gallons of a 1.5% grade, what is x in terms of y &z?.
A)y+3z
b)y+z
4
c)2y+3z
d)3y+z
e)3y+4.5z

Ans: A