Question (2) [10 marks] Consider the following optimal tableau, where Si and S2 are slack variables added to the original problem: 0 0.4 4 C $9 $7 $0 $0 SOLUTION V Mix X s, S, QUANTITY $9 1 0.6 -0.2 18 7 X 0 1 0.2 Z $9 $7 $4 SI $190 G-Z -4 -1 a) Find the range of values of the profit of the variable X, for which the current basis remains optimal? b) How much the right-hand side of the second constraint could be changed without changing the solution mix? 0 0 c) What will be the profit if the right hand side of the first constraint were changed by adding 5 units