Two copper vessels A and B have the same base area but of different...

Pressure, $\mathrm{P}=h \rho g$ In above equation, $\rho$ represents density of water, $g$ represents acceleration due to gravity and $h$ is the height of the vessel. As both vessels have same height and containing water, then densities are also same. Hence, the pressure on the base area of vessels $A$ and $B$ is same.