David is a college professor who does some consulting work on the side. He uses 25% of his home exclusively for the consulting practice. He is single and 63 years old. His AGI (without consideration of consulting income) is $40,500. Other information follows:

Income from consulting business$4,075Consulting expenses other than home office1,560Total costs relating to home:Interest and taxes6,545Utilities1,530Maintenance and repairs465Depreciation (business part only)1,575