Drop in pressure, what volume is left?

[Hexxor]

Homework Statement

There is a vessel with 10 Liters of Liquid Nitrogen.
The normal pressure is 100 Psi.
After a couple hours the pressure is dropped to 47 Psi because of leak in the vessel.

How much of the Liquid Nitrogen did we lose/is left in the vessel?

Homework Equations

I'm really not sure. I thought about P1V1 = P2V2, but I don't think that will work here.

The Attempt at a Solution

Using P1V1 = P2V2 I got an answer, but I think that will only work for a closed system (drop in pressure means increase in volume and vice versa)

So, does anyone have an idea how to solve this?

 

[Chestermiller]

What is the exact wording of this problem (not your paraphrasing)? There seems to be information missing.

Chet