16. Lily went from her office in Portland to Lisbon on business. While there, she spent part of the time on vacation. How much of the air fare of $5,000 can she deduct based on the following assumptions:

a. Lily was gone five days (i.e., three business and two personal).

b. Lily was gone for five dayys (i.e, four business and one personal)

c. Lily was gone five weeks (i.e., three business and two personal).