Which law states that the effect of pressure is the same for all portions of a confined fluid?

Why does the bottom of a bottle filled with liquid break when the cork is hit?

$A$ hydraulic lift is shown in the figure. The movable pistons $A, B$ and $C$ have radii of $10 \,cm, 100 \,cm$ and $5 \,cm$ respectively. If a body of mass $2 \,kg$ is placed on piston $A$, what are the maximum masses that can be lifted by pistons $B$ and $C$ respectively?

$A$ hydraulic automobile lift is designed to lift cars with a maximum mass of $3000 \; kg$. The area of cross-section of the piston carrying the load is $425 \; cm^{2}$. What maximum pressure would the smaller piston have to bear?

The area of cross-section of the wider tube shown in the figure is $800 \ cm^2$. If a mass of $12 \ kg$ is placed on the massless piston,the difference in heights $h$ in the level of water in the two tubes is ........ $cm$.

$A$ hydraulic press can lift $100\, kg$ when a mass $'m'$ is placed on the smaller piston. It can lift ......... $kg$ when the diameter of the larger piston is increased by $4$ times and that of the smaller piston is decreased by $4$ times,keeping the same mass $'m'$ on the smaller piston.