The answer is 40 grams. If gold is 20 grams per mL and you have 2 mLs, you get 40 grams of gold. Just add 20 + 20 or multiply 2 x 20 to get 40.
The final step in a typical titration, that is here an acid base one would be to finally find the concentration of your unknown substance whether that be the acid or the base. The other steps are used before this to come to the correct calculation and conclusion.
The size of the object and the distance between the objects.