I am taking liner programming. Can u help this question?

1. Table below illustrates a number of possible duties for the drivers of a bus company. We wish to ensure, at the lowest possible cost, that at least one driver is on duty for the each hour of the planning period (9 am to 5 pm). Duty hours 9-1 9-11 12-3 12-5 2-5 1-4 4-5 Cost 30 18 21 38 20 22 9 (a) Formulate this problem as a shortest path problem. Draw the corresponding graph. (b) Does it have an acyclic ordering? (c) Find the optimal solution using dynamic programming algorithm