3. The following is a simplex tableau for a linear programming problem: 60 50 45 50 0 0 0 0 Basic G Variables Quantity x $2 x4 51 $ " 0 $1 50 x4 60 x1 0 2525 20 0 1 0 0 1 0 0 0 15 0 0 0 1 0 1 0 0 12 1 1/2 0 0 0 0 1/10 0 54 45 0 0 8 6 0 -6 0 I 4 1,470 60 30 0 50 50 6 0 9-3 0 20 45 0 0 -50 -6 0 a. Is this a maximization or a minimization problem? b. What are the values of the decision variables in this tableau? c. What are the values of the slack variables in this tableau? d. What does the c-z, value of "20" in the "x2" column mean? e. Is this solution optimal? Why? If the solution is not optimal, determine the optimal solution