Two communicating vessels are filled with water, the cross-sectional area of a narrow vessel (A)

Two communicating vessels are filled with water, the cross-sectional area of a narrow vessel (A) is 12 times smaller than that of a wide one. A weight of 500 g was placed on piston A. What mass of weight must be placed on piston B so that the pressures acting on the surface of the water become equal?

In this case, we are dealing with a hydraulic press, with a gain K equal to 12.
Let us find how much mass M must be put on piston B if a mass m equal to 500 g is put on piston A:
M = K * m = 12 * 500 = 6000 g = 6 kg.
Answer: in order for the pressure on the surface of the water in both vessels to be equal, a weight of 6 kg must be put on piston B.