Grades

[moneyman]

Three grades of milk are 1%,2% and 3% fat by volume. If x gallons of the 1% grade,y gallons of the 2% grade and z gallons of the 3% grade are mixed to give x+y+z gallons of a 1.5% grade,what is x in terms of y and z??

y+3z
y+z/4
2y+3z
3y+z

[samirpandeyit62]

x gallons of 1% grade will have x/100 fat

y will have 2y/100

z will have 3z/100

so total fat in x+y+z =x+2y+3z/100

now given total fat in x+y+z = 1.5%

i.e 1.5/100 * (x+y+z)

so x+2y+3z/100 = 1.5/100 * (x+y+z)

so x =y + 3z

ans should be A