Rex’s 30% interest in the company profits entitles him to 30% of the profits in a given year, regardless of how much he chooses to withdraw as dividends. In 2017, his 30% of the $400,000 is 120,000. In 2018, the partnership had $600,000 in income, and Rex’s share of these profits is 180,000. His combined gross income is 120k + 180k = $300,000. Note that we do not deduct his investment because his has simply exchanged an asset, cash, for another asset, interest in the company, and therefore does not expense the investment amount.