dear student,
IDEAL CONDITION – The pressure inside and outside the balloon always remains same, it is not to be mentioned. Had it not been the same, excessive pressure inside the balloon might have burst it or excess outside pressure might have compressed it.
It is this very reason that balloons either become limp after sometime or may even grow bigger, just to balance pressure inside and outside of the balloon.
REAL CONDITION – the pressure inside the balloon is considered more because even the tension (force) in balloon membrane appears to pull inwards, which imparts additional pressure on inside air.
the reason for gas molecules to flow out through hole is due to effusion(rushing through small holes), since gas molecules are very small and always in constant random motion, also confined in close space inside the balloon.
