MathDB
Oil Tank

Source:

February 11, 2009
geometryrectangle

Problem Statement

A cylindrical oil tank, lying horizontally, has an interior length of 10 10 feet and an interior diameter of 6 6 feet. If the rectangular surface of the oil has an area of 40 40 square feet, the depth of the oil is: (A)\ \sqrt{5} \qquad (B)\ 2\sqrt{5} \qquad (C)\ 3\minus{}\sqrt{5} \qquad (D)\ 3\plus{}\sqrt{5} \\ (E)\ \text{either }3\minus{}\sqrt{5}\text{ or }3\plus{}\sqrt{5}