Pressure questin (fast, just to check)

Question

osanseviero · Answer

h= 0.75 m
density = 1.35 * 10^4 kg/m3

P=0.75*1.35*10^4*9.81 ? Do I need to change the units of density? the answer is 99,326 and seems too big

osanseviero · Answer

Btw...how can I calculate the total pressure of two different liquids (ex: water and oil) at the bottom of the recipient? Do I add them?

anonymous · Answer

No. Atmosphere is 101,000 N/m2, for example. The liquid density is 13.5 times that of water, probably mercury. 30 inches of mercury pressure is 0.75m=75cm, and is close to typical atmospheric pressure.

osanseviero · Answer

So my answer is probably right...So what do I do with two different liquids? Do I add the pressure?

anonymous · Answer

If one liqid is atop the other, then add the pressures by getting the pressure at the interface from the thickness and density of the top liquid and then from there adding the pressure from the other liquid down to the bottom. 
Pressure will be P bottom= (density1 thickness1 + density2 thickness2) (g).
I don't know your geometry, but this gives you the principle.