Answer:
The cost of taking a night off is $140.
Step-by-step explanation:
Giving the following information:
He has a 6 hour shift and makes $15 per hour. His friends however invite to go to dinner ($20) and see a good concert ($30).
The economic cost incorporates the opportunity cost of not working.
Economic cost= (20 + 30) + (6*15)
Economic cost= $140
The cost of taking a night off is $140.