Answer:
Let the volume of the cube be V and the fraction of cube outside water be f.
Thus, volume of ice inside water = volume of water displaced =(1−f)V
Under equilibrium,
Weight of ice = Weight of water displaced
⟹Vρ
ice
g=(1−f)Vρ
water
g
⟹(1−f)=
10
9
⟹f=
10
1
Thus, the percentage of volume outside water =10%