Assume that the current market price of a share is Rs. 100. A company has announced a rights issue of one share for every four shares held, at a subscription price of Rs. 80 per share. The ex-right price of the share is Rs. 90. If an investor holds 1000 shares of the company, what would be the theoretical ex-right price after the rights issue and how many additional shares would the investor need to buy to maintain his original percentage ownership in the company?