Charlie sold Whiteacre for $40,000 cash and the buyer assumed Charlie's $19,000 mortgage on the property. Charlie

Question:

Charlie sold Whiteacre for $40,000 cash and the buyer assumed Charlie's $19,000 mortgage on the property. Charlie paid a realtor commission of $2,000 on the sale. What is his realized gain or loss if Whiteacre's adjusted basis is
a. $47,000?
b. $67,000?