Mal-Wart truck fleet hires temporary drivers for four-and eight hour shift during holiday sales season. Four-hour shifts starts at 6am, noon, and 2pm, eight-hour shifts starts at 6am,8am, noon, and 2pm.

The number of drivers needed varies during the day. The table below shows the minimum number of drivers that are needed each two-hour time block through out the day.(for example Mal-Wart needs 37drivers from 8am to 10am.)
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time 6am 8am 10am noon 2pm 4pm 6pm 8pm

drivers needed 63 37 21 33 48 55 27 17

A drivers pay depends on the hours worked. a driver gets paid $10per day, plus $7 per hour worked, plus a $1 hour premium for each hour worked before 8am or after 6pm. Mal-Wart would like to pay as little as possible while having enough drivers at all times.

1. Formulate a linear programming model for this problem and type it in worksheet 1 of your Excel file.

2.In worksheet 2 of your excel file formulate an excel model that corresponds to your mathematical model and use solver to find the optimal solution to the problem