The 10 g mass is extraneous information. You don't need it.
P1V2 = P2V2.
A 10-g mass of krypton occupies 15.0 L at a pressure of 210 kPa. Find the volume of the krypton when the pressure is increased to 790 kPa.
2 answers
okay. The 10 g mass was throwing me off.