The pressure exerted by a certain liquid at a given point varies directly as the depth of the point beneath the surface of the liquid. The pressure at 50 f

Question

The pressure exerted by a certain liquid at a given point varies directly as the depth of the point beneath the surface of the liquid. The pressure at 50 feet is 400 pounds per square inch. What is the pressure at 30 feet? 

Answer 1

Let P = the pressure and d = the depth. Since it's a direct variation, then you can say P = k*d, where k is the constant of variation. Use your first example to find k. Then you can find P using that k and the new d.