1. Four workers, A, B, C and D, are to be assigned to four tasks, 1, 2, 3 and 4. Each worker must be assigned to just one task and each task must be done by just one worker.

Worker A cannot do task 4 and worker B cannot do task 2. The amount, in pounds, that each worker would earn if assigned to the tasks, is shown in the table below. Reducing rows first, use the Hungarian algorithm to obtain an allocation that maximises the total earnings. You must make your method clear and show the table after each stage.