n A promoter comes up to you and offers to give you a free ticket to a concert that night. The ticket usually costs $100. You decide to attend the concert. The concert takes three hours and costs you $20 for transportation. If you had not attended the concert, you would have worked at your part- time job for $20 an hour. What is the cost to you of attending the concert? 0 $70 0 $20 0 $80 O$0