Example 1

UC Davis intend to install new chairs for the lecture halls. Three contracters submitted seperate bids for the work in each of htese lecture halls. The bits (in 1000-dollars units) are listed in the following table.

Contractors	Left Hall	Right Hall	Middle Hall
contractor 1	25	44	36
contractor 2	28	40	40
contractor 3	23	50	35

Each contractor can stall the chairs for only one lecture hall. To which Lecture hall should each constractor be assigned to, in order to minimize the sum of the corresponding bids?