. A delivery service for cooked food has contracts with many restaurants which do not have their own delivery service. Customers place their orders on-line with the delivery service, stating the items they wish to order and the restaurant at which the order will be made. The delivery service then sends each order to the restaurant, picks it up when it's ready, and delivers it to the customer. Though some delivery services work on a per-order basis, this one pays its drivers by the hour. Deliveries begin at 7 a.m. each day, and continue until 2:59 a.m. the next morning. Their drivers work two four-hour shifts per day. For some drivers, the two shifts are consecutive (effectively one eight-hour shift), but other workers work split-shifts, with a four hour gap between their shifts. All drivers earn a base rate of $17 per hour. In addition, there is a per-day bonus of $14 paid to each driver who works on a split-shift. The delivery service has the following daily requirements: Shift Minimum Number Index Time of Day of Drivers Needed 1 7 a.m. to 10:59 a.m. 18 2 11:00 a.m. to 2:59 p.m. 37 3 3:00 p.m. to 6:59 p.m. 15 4 7:00 p.m. to 10:59 p.m. 30 5 11:00 p.m. to 2:59 a.m. 12 Subject to meeting all its requirements for workers, the delivery service wishes to minimize its daily labour cost (regular and bonus). Formulate the model so that the $17 and the $14 are entered only once.

a) formulate an algebric expression

b) USE EXCEL SOLVER OR LINGO to solve this model

c)state the solution in words