Well, one of the most important formulas you will learn in Chemistry(AP or Honors) is PV = nRT, or Pressure*Volume = mole*R*Temperature. It states that the container is rigid, so volume can't change. No molecules are going in or out of the container, so moles can't change. Finally, R is a constant value, so it is always the same. This means that As T increases, P increases at the same rate. Thus you get (P1/T1 = P2/T2) where P1 and T1 is the pressure and temperature for the first container, and P2 and T2 are the pressure and temperature for the container after change. Plugging in values, you should get 0.96/(25 + 273) = 1.25/(T2) (Note that I add 273 because T is in kelvin, and you are given celsius), or T2 = 388k. This 388 - 273 = 115 C