The fraction of a floating object of volume V0 and density d0 above the surface of a liquid of density d will be
d0d
dd0d+d0
d−d0d
dd0d−d0
For the floatation V0d0g=Vin dg⇒Vin =V0d0d
∴Vout=V0−Vin=V0−V0d0d=V0d−d0d⇒VoutV0=d−d0d