The lake isle of innisfree

Lake Isle of Innesfree

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 ?

A sacred lake is

The angle of elevation of a stationary cloud from a point 25 m above a lake is 30^(@) and the angle of depression of its reflection in the lake is 60^(@) . What is the height of the cloud above that lake-level ?

The angle of elevation of a stationary cloud from a point 2500 feet above a lake is 30^@ and the angle of depression of its reflection in the lake is 45^@ .Find the height of cloud above the lake water surface .