If pressure at half the depth of a lake is equal to 2/3 pressure at the bottom of the lake then what is the depth of the lake?

Pressure at bottom of the lake = Po+ hpg and pressure at half the depth of a lake = P0+ h2ρgAccording to given conditionP0+12hρg = 23(P0+hρg)  ⇒13P0 = 16hρg⇒h = 2P0ρg = 2×105103×10 = 20 m.