It is an ideal gas therefore we can use the ideal gas equation to solve the problem. The ideal gas equation is expressed as PV = nRT. First, we solve the amount of the gas in moles using the said equation and the first conditions.
(2.0 atm) (5.0 x 10^3 cm^3) = n (82.0575 atm.cm^3/mol.K)(215 K)
n=0.5668 mol
Using the second conditions given, we obtain the new pressure.
P (4.0 x 10^3) = 0.5668 x 82.0575 x 265
P= 3.08 atm
