c
(c) Let the total volume of ice-berg is \(V\) and its density is \(\rho\). If this ice-berg floats in water with volume Vin inside it then \({V_{in}}\sigma g = V\rho g\) ==> \({V_{in}} = \left( {\frac{\rho }{\sigma }} \right)\;V\)[\(\sigma = \)density of water]
or \({V_{out}} = V - {V_{in}} = \left( {\frac{{\sigma - \rho }}{\sigma }} \right)\;V\)
==> \(\frac{{{V_{out}}}}{V} = \left( {\frac{{\sigma - \rho }}{\sigma }} \right) = \frac{{1000 - 900}}{{1000}} = \frac{1}{{10}}\)
\({V_{out}} = 10\% \) of \(V\)