A man sells 4000 common shares of a Company x (each of par value Tk. 10), which pays a dividend of 40% at Tk. 30 per share. He invests the sale proceeds in ordinary shares of Company Y (each of par value Tk. 25) that pays a dividend of 15%. If the market value of Company Y is Tk. 15, find the number of shares of Company Y purchased by the man.