Abstract: In this paper, the writer will give a concrete counter-example to show that an important argument in[1]and[2](i. e. in this problem the extreme-point and the optimum mass Rat ios were the same) was Somewhat incorrect in general.
Then how to find the optimum mass Ratios in Reneral situation? To do this, The writer went a step further to discuss the work of[1],[2], and obtained not only some important new results such as the existance and uniqueness of the extreme-points in[2], but also proposed the idea of theoretical permissible region as well as the idea of practical permissible region etc. Then proposed a method for determining the optimum mass Ratios, Hence some results in[1] and[2] were improved and perfected.