Final answer:
The manager can afford at most 8 employees for the day.
Step-by-step explanation:
To determine how many employees the manager can afford for the day, we can set up an inequality using the given information. Let x represent the number of employees the manager can afford. The total cost for operating costs and payroll is $400, and it costs $80 each day to operate the restaurant. In addition, it costs $40 a day for each employee. Therefore, the inequality is 80 + 40x ≤ 400.
To solve this inequality, we can subtract 80 from both sides: 40x ≤ 320. Then, divide both sides by 40 to isolate x: x ≤ 8.
Therefore, the correct answer is option 3) x ≤ 8. The manager can afford at most 8 employees for the day.