Bunuel wrote:

How many pounds of fertilizer that is 10 percent nitrogen must be added to 12 pounds of fertilizer that is 20 percent nitrogen so that the resulting mixture is 18 percent nitrogen?

(A) 3

(B) 6

(C) 12

(D) 24

(E) 48

10-------------20

--------18-------

2---------------8

Hence the ratios in which the mixtures are to be added are 1:4

Since we are adding 12 pounds of the 20 percent nitrogen mixture,

we will need 3 pounds of the 10 percent nitrogen mixture, so that

the resulting mixture has 18 percent nitrogen.

Therefore, we need 3 pounds of fertilizer mixture having 10 percent nitrogen(Option A)

_________________

You've got what it takes, but it will take everything you've got