Mr. Monty owned an office building that he had purchased at a cost of $600,000 and that now had an adjusted basis of $400,000. In the current year, he traded it to a person who was not related to him

Mr. Monty owned an office building that he had purchased at a cost of $600,000 and that now had an adjusted basis of $400,000. In the current year, he traded it to a person who was not related to him for an apartment house having a fair market value of $500,000. The apartment house has 50 units and rents to individuals. The office building has 25 units and rents to Monty’s businesses. What is Mr. Monty’s recognized gain or loss on this exchange? And why - kindly explain your answer.