To be floating, the gravity force of the iceberg should be same as the buoyancy force that result from the difference of the ice and water density.
The density of ice is 920 and water is 1030, then the difference should be: 1030kg/m3-920kg/m3= 110kg/m3
Let say that the volume of ice below the water is volume1 and the volume above the water(exposed volume) is volume2.
You can get this equation
volume1+volume2= 100%
volume1= 100%- volume2
Insert it into the buoyancy and gravity force will result
buoyancy=gravity
110kg/m3*volume1= 920kg/m3 *volume2
110kg/m3*(100%- volume2)= 920kg/m3 *volume2
110kg/m3 - 110kg/m3*volume2= 920kg/m3 *volume2
110kg/m3 = 1030kg/m3 *volume2
volume2= 110/1030= 0.1067= 10.7%
