Holding 100 shares A, B B shares 100 shares, two kinds of stock are 10 yuan per share, A shares the first get A dividend of 0.40 yuan A year, A total of 10 years, after the tenth of share out bonus, armour for the price of $2 per share will be sold all shares, and armor by 6% at an annual rate of return to dividend income and stock investment income on sale. Shares of B have no dividend income in the first 10 years, and they will receive an annual dividend of 0.80 yuan from the end of the 11th year. If B also invests at an annual interest rate of 6%, and sells its shares after n years. In order to make the cumulative income of Party A and Party B at the time of the sale of the shares of Party B be the same, the sale price of the shares of Party B is calculated for the three cases of n= 15,20 and 25 respectively.