Question: Question 3: A bus company believes that it will need the following number of bus drivers during each of the next five years: year 1, 60 drivers; year 2, 70 drivers; year 3, 50 drivers; year 4, 65 drivers; year 5, 75 drivers. At the beginning of each year, the bus company must decide how may drivers should be hired or fired. It costs $4000 to hire a driver and $2000 to fire a driver. A driver's salary is $10,000 per year. At the beginning of year 1, the company has 50 drivers. A driver hired at the beginning of a year may be used to meet that year's requirements and is paid full salary for the year. Formulate and solve an LP to minimize the bus company's salary, hiring, and firing costs over the next five years.

Please enter the number of drivers hired at the beginning of year 2 as the answer.