Ron, david, and mary formed widget, inc. ron and david each received 40% of the stock, and mary received the remaining 20%. ron contributed land with an fmv of $70,000 and an adjusted basis of $20,000. the corporation also assumed a $30,000 liability on the property. david contributed land with an fmv of $30,000 and an adjusted basis of $15,000. david also contributed $10,000 in cash. mary received her stock for services rendered. she normally would bill $20,000 for these services. what is david's basis in the corporate stock received?