Mark receives a proportionate current (nonliquidating) distribution. At the beginning of the partnership year, the basis of his partnership interest is $80,000 and his share of the partnership's income for the year is $20,000. During the year, the received a cash distribution of $40,000 and a property distribution (basis of $30,000, fair market value of $25,000). In addition, Mark's share of partnership liabilities was reduced by $10,000 during the year. How much gain or loss does Mark recognize; what is his basis in the property he received; and what is his remaining basis in the partnership interest?