Steve owns a rental property with an adjusted basis in Steve's hands of $100

Steve owns a rental property with an adjusted basis in Steve's hands of $100,000. Steve's property is subject to a mortgage of $20000. Steve transfers his rental property to Terry in exchange for $10000 cash and an apartment building with a fair market values of $150,000 . Terry's property has no mortgage on it. Terry assumes Steve's mortgage of $20,000 as part or the terms of the exchange.   What is Steve's RECOGNIZED gainon this transaction?