The answer may be zero.

Determine the taxpayer's gross income for tax purposes in each of the following situations:

a$.$ Eduardo, a cash basis taxpayer, traded a corporate bond with accrued interest of $$300$ for corporate stock with a fair market value of $$12,000$ at the time of the exchanges. Eduardo's cost of the bond was $$10,000.$ The value of the stock had decreased to $$11,000$ by the end of the year. Show all calculations and include ALL income.

b$.$ Marcus needed $$10,000$ to make a down payment on his house. He instructed his broker to sell some stock to raise the $$10,000.$ Marcus' cost of the stock was $$3,000.$ Based on his broker's advice, instead of selling the stock, he borrowed the $$10,000$ using the stock as collatera for the debt. Explain your answer.

c$.$ Amy's boss gave her two tickets to the Rabid Rabbits rock concert because she met her sales quota. At the time she received the tickets, each ticket had a face price of $$200$ and was selling on eBay for $$300.$ On the date of the concert, the tickets ere selling for $$250$ each. Amy and her son attended the concert. Explain your answer.