I am confused on why the answer to this question is not 4 and then 3. What is the answer to this question

Question 8 A convenient store owner is contemplating opening the store for business a few extra hours everyday after 6:00 p.m. (currently the store closes at 6:00 p.m.} The marginal benets of additional hours (revenues earned in those hours} decline as we move further into the night as fewer people shop in late hours. In particular, the following are the marginal benets for different hours: 10:00 to 11:00 pm. $700 The marginal cost of operation will also increase with the number of hours. For example, workers will ask for additional wages. The following table shows the marginal costs associated with those hours. 6:00 to 7:00 pm. $300 7:00 to 8:00 pm. $500 8:00 to 9:00 pm. $700 9:00 to 10:00 pm. $900 10:00 to 11:00 pm. $1,100 This information leads us to believe that the store will be open for business an additional |:| hou rs. (Okay, this was too easy). Question 9 Consider the information presented in Question 8. Two things happen. The price of oil increases and at the same time government passes a new minimum wage law that increases the minimum wage by a few dollars. As a result of these two even ts, the marginal cost of operation increases by $400 for each and every hour. Because of this increase in marginal cost, the store owner will open the shop for an additional |:| hours