Just rearrange it to solve for P[tex]_{2}[/tex], which is what you want to know.

Then you just have to figure out how many liters of air the diver will breathe in that hour. It tells you the volume of each breath, and how many breaths he'll take (breaths per minute times sixty minutes). So that'll give you the V[tex]_{1}[/tex] that he needs, whereas the V[tex]_{2}[/tex] is the volume of the tank.

And I still don't know why the Latex codes are displaying those numbers as superscripts rather than subscripts....