This paper presents a method to compute the average relative volatility when Fenske Equation is used to obtain the minimum number of stages at total reflux.

The developed optimum design method based on the least paste theory is verified by test data.

A visualization method of solving the theoretical stage number was a dvanced based on McCabe-Thiele graphical principle and using Excel.

Inquire into several applications of the meaning and function of the progression theory,progression illustrated with examples theory.

Analysis on the least gears in Gear Mechanism;