1. Is the following tableau optimal 21 x2 23 24 25 RHS X2 0 10 1/60 2/3 23 2 0 1 1/2 0 10 25 1 0 0 5/2 1 19 400 31 0 460 under the circumstances below? If it is optimal, also state the value of the optimal objective function. (a) The problem is a minimisation problem and the z-row of the tableau was initialised with the cost vector (c). (b) The problem is a maximisation problem and the z-row of the tableau was initialised with the cost vector (c).