T is proportional to P and to V, so
T2/T1 = (P2/P1)(V2/V1) You know T1,P1,V1 and you change to P2,V2 - solve for T2
This kind of proportional thinking requires absolute units. Degrees C + 273.15 = Kelvin must be applied before you substitute. Your answer will be in Kelvin and you will have to convert it back to Celsius. Other units are fine as long as they are consistent - you can use liters or m^3 or ft^3 as long as both volumes are in the same units.
Good Luck!