Dear student
1. centre of buoyancy is the point on an immersed part of the body through which all the buoyant forces are assumed to act .
2. pressure = Force/Area
3. weight of body (v) x density of the body x gravity= volume water displaced x density of water x gravity.
volume water displaced will be equal to the volume of the immersed part of the body so volume water displaced will be 2/3 of volume of body , density of water is 1000 kg /m3
v x density of the body x gravity=2v/3 x 1000 x gravity density of the body= 2000/3=666.66kg/m3
4 Density of that liquid will be higher in which more amount of body is outside the liquid surface.
thus it proves d1 < d2 <d3.
Regards