Re: Pressure question
Indeed. And the answer is true.
That has been called "hydraulic paradox". Applying a small amount of force on a small surface can bring about a larger force on a larger surface, because the pressure in a closed vessel of fluid is uniform (neglecting gravity etc.).
Note that if you actually move the surfaces, then the pressure inside stays constant if the volume stays constant. Which it does if the volume changes on both surfaces cancel out. And they do, if the smaller surface moves for a larger distance than the larger surface.
Effectively, a fluid can amplify forces exactly as levers do - large movement of a small force can cause small movement of a large force.
And the 4 cm squared side will, of course, have a smaller force acting on it than the 6 cm squared side.