4. Four workers, \(\mathrm { A } , \mathrm { B } , \mathrm { C }\) and D , are to be assigned to four tasks, \(1,2,3\) and 4 . Each worker must be assigned to only one task and each task must be done by only one worker. Worker A cannot do task 3 and worker D cannot do task 2
The cost, in pounds, of assigning each worker to each task is shown in the table below. The total cost is to be minimised.
Formulate the above situation as a linear programming problem. You must define your decision variables and make the objective function and constraints clear. You do not need to solve this problem.