 
 <translate> Three grades of milk are 1 percent, 5 percent and 3 percent fat by volume. If x gallons of the 1 percent grade, y gallons of the 5 percent grade, and z gallons of the 3 percent grade are mixed to give x+y+z gallons of a 7 percent grade, what is x in terms of y and z?
Options:
(A) -1y - 2z
(B) (y +z)  / 4
(C) 2y + 3z
(D) 3y + z
(E) 3y + 4.5z Hmmm, my stream of consciousness: <hau> Nau'o'i uku na madara suna da kashi 1 cikin ɗari, kashi 5 cikin ɗari da kuma kashi 3 cikin ɗari na mai. Idan x gallons na kashi 1 cikin dari, y gallons na kashi 5 cikin dari, da z gallons na kashi 3 cikin dari an haxa su don samun x + y + z gallons na kashi 7 cikin dari, menene x dangane da y da z? Zaɓuɓɓuka: (A) -1y - 2z (B) (y + z) / 4 (C) 2y + 3z (D) 3y + z (E) 3y + 4.5z Hmmm, rafi na sani: 