The density of ice is 0.9 gcc^–1 and that of sea water is 1.1 gcc^–1.  An ice berg of volume V is floating in sea water. The fraction of ice berg above water level is

Let, v be the volume of ice-berg outside the sea water while floating. Therefore, volume of ice-berg inside the sea water = (V -v). As ice-berg is floating, so weight of ice-berg =weight of sea water displaced by ice-berg.

$\begin{array}{l}V\times 0.9\times g=(V-v)\times 1.1\times g\\ 1.1v=1.1V-0.9V\\ v/V=0.2/1.1=2/11\end{array}$