nakib77 wrote:

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 1.5 % grade, what is x in terms of y and z?

a. y+3z

b. (y+z)/4

c. 2y+3z

d. 3y+z

e. 3y+4.5z

1% of x has .01x of fat, 2% has .02y of fat.. and .03 of fat..

total fat = .015..

.01x + .02y + .03z = .015

or.. x = 1.5-(2y+3z)

so.. x in terms of y and z is 2y + 3z.. constant can be ignored

_________________

Success is my only option, failure is not -- Eminem