急!!!!!就要考試了，請各為幫忙解題阿!!!

b342785

1.Three grades of milk are 1 percent , 2percent and 3percent fat by volume . If x gallons of the 1percent grade , y gallons of the 2 percent grade , and z gallons of the 3percent are mixed to give x+y+z gallons of a 1.5 percent 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

大家幫個忙吧~please!

yunli03

 1%X+2%Y+3%Z=1.5%(X+Y+Z) 就可以求出了.

ericot701

选A吧

(1%x+2%y+3%z)/(x+y+z)=1.5%