Gmat Prep PS

[manju_ej]

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?

[sudhir3127]

hey manju..
u shud actually post the answers as well to questions...

here it goes..

my best bet is to plug in the numbers..

let y = 2 and Z = 4

x gallons of 1% = 0.01x gallons of fat

2 gallons of 2% = 0.02*2 = 0.04

4 gallons of 3% = 0.03*4= 0.12

total fat = 0.01x + 0.04 + 0.12 = 0.01x + 0.16

total volume = x + 2 + 4 = (x + 6) gallons


(0.01x + 0.16)/(x + 6) = 0.015 ..( given in the question)

solve for X

X= 14

hence it should be Y + 3Z.

hope its clear.. let me know if have any doubts..