To solve this problem we will apply the Pascal principle. This law establishes that the pressure exerted on an incompressible fluid and in equilibrium within a container of non-deformable walls is transmitted with equal intensity in all directions and at all points of the fluid.
Mathematically the relationship is given as

Since it is a circular piston the area will be given as

Replacing,


Our values are given as

Replacing we have that


Therefore the wieght that can be lifted is 6250N