A layer of kerosene 20 cm high was added to the left knee of the u-shaped tube filled with water.

A layer of kerosene 20 cm high was added to the left knee of the u-shaped tube filled with water. How much does the water level rise in the right knee?

hk = 20 cm = 0.2 m.
ρк = 800 kg / m ^ 3.
ρw = 1000 kg / m ^ 3.
hв -?
The water level will rise to such a height that the pressure of the water column Pw is equal to the pressure of the kerosene column Pk.
Рв = Рк.
The hydrostatic pressure of the liquid is determined by the formula: P = ρ * g * h. Where ρ is the density of the liquid, g is the acceleration of gravity, h is the height of the liquid.
Pв = ρв * g * hв.
Pк = ρк * g * hк.
ρв * g * hв = ρк * g * hв.
hв = ρк * g * hк / ρв * g = ρк * hк / ρв.
hv = 800 kg / m ^ 3 * 0.2 m / 1000 kg / m ^ 3 = 0.16 m.
Answer: the water level will rise to a height of hw = 0.16 m.