a) Develop a linear/integer programming model to minimize total cost. Assume that 1 ) net stock at the end of October must be at least 100 units; 2) Overtime production in a month can at most be 50% of the regular time production.. Solve your model using Excel Solver. b) Suppose we need to have safety stock at the end of each month, and it is to be equal to 300 units. Resolve the problem using Solver