A bit dumb question because it is really difficult to imagine it. :-
Pressure is force per area. Talking about gases, the pressure is said to be the force molecules exert on walls of let's say a balloon.
Usually in examples of Boyle's law, our teachers mention hot air balloon, that the size of balloon increases as pressure decreases.
But at as height increases pressure decreases because there are less molecules above us.
How will the pressure of molecules outside the balloon effect the pressure of molecule inside the balloon.