Homework help - gas laws and stoichiometry!

[bobo]

A candle is burnt inside a sealed container of oxygen gas with a volume of 1500 cm3 at 25oC. Once the reaction is complete and the container has cooled to 25.0oC, what will the pressure be inside the container? Assume the candle has no volume, that all the oxygen is consumed, that candle wax has the empirical formula CH2 and that all combustion is complete?

The answer is 67.3 kPa, but I can't go about solving this. Thanks.