Okay, I'm kinda stuck with the following so help would be greatly appreciated.
The question is..
Two small flasks with closed stopcocks are attached by short tubes to a large flask. The large flask and connecting tubing is well evacuated. One small flask of volume 25 mL, contains oxygen at the pressure of 101.3 kPa, while the other, of volume 75 mL, contains helium at a pressure of 70.9 kPa. The stopcocks of the small flasks are opened so that the two gases mix and expand into the evacuated volume. The total volume of the whole apparatus is 10.0 L. Calculate the partial pressures of oxygen and helium and the total pressure.
Since no temperature was given, I wasn't sure how to go about doing this.