Metro telecom systems sells computer system. The company has divided its customers base into 5 regions and it has 15 salespeople who sell these computer systems. The company want to allocate these 15 salespeople to 5 regions so that they can maximize daily sales revenue. The relationship between daily sales of a region and number of salespeople (xi) allocated to this region is sales = a - (b/xi), while a and b are different in different regions. Parameter a and b of different regions are given as the following. For example, suppose number of salespeople assign to region 1 is x1, the sales in region 1 is 15000-9000/x1.

Region

1 2 3 4 5

a 15000 24000 8100 12000 21000

b 9000. 15000. 5300. 7600 12500

Because some of the regions are in urban areas and some are not, salepeople's expense will differ among regions. The company has a daily expense budget of $6500, and the daily expenses per salesperson for each region is $355 for region 1, $540 for region 2, $290 for region 3, $275 for region 4, and $490 for region 5.

• Which of the following options are the correct constraints?

a. x1 + x2 + x3 + x4 + x515; 355x1 + 540x2 + 290x3 + 275x4 + 490x5 6,500

b. x1 + x2 + x3 + x4 + x515; 355x1 + 540x2 + 290x3 + 275x4 + 490x5 6,500; xi0

c. (15000-9000/x1) + (24000 - 15000/x2) + (8100-5300/x3) + (12000 - 7600/x4) + (21000-12500/x5) 6500

d. x1 + x2 + x3 + x4 + x56500; 355x1 + 540x2 + 290x3 + 275x4 + 490x5 15; xi0

• According to the above information, what would be the appropriate objective function?