The table below shows the marginal benefit that Khaled earns from keeping his store open one more hour. Khaled has a marginal cost of $60 per hour. Khaled stays open 20 hours.

1. Do you think Khaled's decision to stay open for 20 hours is optimal? (Yes or No) Why? (Not more than 4 lines)

2. How many hours do you advise Khaled to stay open? (Write number) Why? (Not more than 4 lines)

Hours Marginal Benefit Per Hour 20 180 21 120 22 80 23 60 24 40