A cylindrical vessel is filled with equal amounts by weight of mercury and water. The overall height of the two layers is 29.2 cm. Specific gravity of mercury is 13 . 6. Then the pressure of the liquids at the bottom of the vessel is

 If x cm be the height of mercur5r column, then the height of water column be 13'6 x cm.
$\therefore \mathrm{x}+13\cdot 6\mathrm{x}=29\cdot 2\text{ or }\mathrm{x}=2\mathrm{cm}$ So, height of mercury column = 2 cm and height of water column=27.2 cm (equivalent to 2 cm of mercury column) 
pressure at bottom = [2 cm + 2 cm) = 4cm of mercury.