In early July, Mike Gottfried purchased a $70 ticket to the December 15 game of the Chicago Titans. (The Titans belong to the Midwest Football League and play their games outdoors on the shore of Lake Michigan.) Parking for the game was expected to cost approximately $22, and Gottfried would probably spend another $15 for a souvenir program and food. It is now December 14. The Titans were having a miserable season and the temperature was expected to peak at 5 degrees on game day. Mike therefore decided to skip the game and took his wife to the movies, with tickets and dinner costing $50. The sunk cost associated with this decision situation is:

Possible answers

a. 20

b. 50

c. 70

d. 107

e. None of these

Please show you calculation and explain the answer. I sunk cost has already been incurred and does not impact future action. I think the answer should be 70, since the tickets were purchased in July. However, after looking at other sources on chegg the answer is listed as 50. It doesn't make sense to me.