Melissa recently paid $400 for round-trip airfare to San Francisco to attend a business conference for three days. Melissa also paid the following expenses: $250 fee to register for the conference, $300 per night for three nights lodging, $200 for meals, and $150 for cab fare.

Suppose that Melissa's permanent residence and business was located in San Francisco. She attended the conference in San Francisco and paid $250 for the registration fee. She drove 100 miles over the course of three days and paid $90 for parking at the conference hotel. In addition, she spent $150 for breakfast and dinner over the three days of the conference. She bought breakfast on the way to the conference hotel and she bought dinner on her way home each night from the conference.

What amount of the travel costs can Melissa deduct as business expenses?