Pam, Sergei, and Mercedes arc all one-third partners in the capital and profits of Oak Grove General Partnership. Partnership debt is allocated among the partners in accordance with their capital and profits interests. In addition to their normal share of the partnership's annual income, Pam and Sergei receive annual guaranteed payments of $20, 000 to compensate them for additional services they provide. Oak Grove's income statement for the current year reflects the following revenues and expenses: In addition, Oak Grove owed creditors $90, 000 at the beginning and $1 50, 000 at the end of the year, and Pam, Sergei, and Mercedes had a tax basis of $50, 000 in their interests at the beginning of the year. Also, on December 31 of the current year. Sergei and Mercedes agreed to increase Pam's capital and profits interest from 33.33 percent to 40 percent in exchange for additional services she provided to the partnership. The current liquidation value of the additional capital interest Pam received is $40, 000. a) What tax basis do the partners have in their partnership interests at the end of the year? b) If, in addition to the expenses listed above, the partnership donated $12, 000 to a political campaign, what tax basis do the partners have in their partnership interests at the end of the year assuming the liquidation value of the additional capital interest Pam received at the end of the year remains at $40, 000