A Corporation exchanged 15,000 shares of its $10 par value common stock held in treasury for a used machine. The treasury shares were acquired at a cost of $40 per share, and are accounted for under the cost method. On the date of the exchange, the common stock had a market value of $30 per share (the shares were originally issued at $30 per share). assume there is $120,000 credit balance on APIC-Treasury stock account on this date. As result of exchange, the retained earnings of Kole will decrease by?