Boyle's Law Calculations help?

I need Help on this problem.

A sample of gas occupies 2.50 L at 1.15 atm of pressure. What is the Volume at standard atmospheric pressure?

My teacher Game me the equation (P1)(V1)=(P2)(V2) and PV=K
I don't really know how to do the problem, setup ect. Can someone help me?
2 answers 2