Please show work for problem in a logical manner, thanks!

1)Dr. Dulbit Drillum, partner in the dental firm of Drillum, Fillum, and Billum, exchanged an office building (market value = $1,538,000) for an apartment building (market value = $1,450,000). Dr. Drillum owes $800,000 on a note secured by a mortgage on his office building, which has an adjusted tax basis of $1,100,000. The building he will receive in the exchange is encumbered with a mortgage that has a balance of $700,000. Dr. Drillum incurs transaction costs of $60,000. Each party agrees to take title subject to the existing mortgage on the substitute building.

a.Assuming that cash will be tendered to balance the equities, how much cash is tendered and by whom?