a little help.. what temperature must a sample of nitrogen...?

Question

To what temperature must a sample of nitrogen at 27 degrees C and 0.625 atm be taken so that its pressure becomes 1.125 atm at constant volume?

Answer 1

Given
PV = nRT
P is 2X, V is constant, n is constant, and R is a constant so
T must be 2X.

So it's around 327.15 C or 600.3 K
======================
Oops, read the pressure as 1.25 which is exactly 2X, it's 1.8X
K = 273.15 + C
T2 = 540.27 K = 267.12 C

Answer 2

27C = 290K

P1/T1 = P2/T2

T2 = P2T1/P1

T2 = (1.125)(290)/(0.625) = 522K = 249C