Calvin lives in San Francisco and commutes to work. In the month of March 2014, he will be taking a direct bus to and from work on Mondays, Wednesdays and Fridays, and he will be driving to Oakland on Tuesdays and Thursdays. He can choose from several options of payment:
- Pay $2 for each (one-way) trip.
- Pay $15 for a day pass
- Pay $29 for a week pass
- Pay $66 for a monthly pass
If Calvin doesn't use the bus otherwise, which option will be the cheapest for him?