5) (20 marks) Answer the following questions using the sensitivity report shown below: a) Report the optimal solution and the optimal value of the objective function. ( 6 marks) b) Calculate the amounts of slack/surplus and comment on what constraints are binding and which ones are non-binding ( 6 marks) c) How much improvement in the objective function will we get if we increase the amount of Steel by 12 more units? ( 3 marks) d) Calculate the optimal value of the objective function (according to this sensitivity report) if the coefficient of x changes to 8 and the coefficient of y changes to 7 simultaneously. Show all of the calculations ( 5 marks)