Depth of Lake Surface for 3x Atmospheric Pressure: 20m

[Neb0]

Homework Statement

At what depth a lake surface is the total pressure 3 times the normal atmospheric pressure?

Homework Equations

P=pgh this is the equation for liquid pressure.

About total pressure we should add also the atmospheric pressure which is pushing from above the surface of the liquid.

The Attempt at a Solution

Pl + Patm=pgh
so, 300kPa=1000kg/m3*10m/s2*h... the answer is 30m, but in the answer key is 20m.

 

[Neb0]

Thank you but don't need. Figured it out.Sorry for posting it too early.