Answer: $105,000
Explanation: In Economics the term profit refers to the amount a company or an individual left with after paying for implicit and explicit cost. Explicit cost means cost paid to others for their services.
While, Implicit cost or opportunity cost is the cost of loosing profits due to choosing one alternative over other. In this case Zippy's salary and his interest on savings is his implicit cost.
therefore,
Economic profit = $250,000 - ( $30,000 + $15,000 + $100,000 )
= $105,000