SOLUTION: Liquid A has 10 grams of element X per liter. Liquid B has 15 milligrams of element Y per cm3 (there are 1000 milligrams in a gram and 1000 cm3 in a liter). It is desired to make 1

Liquid A has 10 grams of element X per liter.

Liquid B has 15 milligrams of element Y per cm3, or, which is the same,
             15 gram of element Y per liter.


To make 18 grams of Z requires 2 grams of X and 16 grams of Y, or, which is the same, 
                               0.2 liters of A and  liters of B.   (*)

 =  .

Therefore, the amounts (*) must be multiplied by   =  each.

So, you need  liters of A and  liters of B.

Again:  =  =  liters of A,  and

        =  liters of B.