Can you tell me how much water you have if I tell you its is
Consider that density is an intensive property. All that means is that no matter how much you have of something, its density remains the same (assuming a uniform material).
The only properties that can change due to the quantity of the thing are extensive properties, i.e. mass, volume, etc.
If you want to know how much that student made... ask for the pudding, and look in there for the proof.