Consider the same linear programming problem as in Question 1 (LP1). Now suppose the profit of chairs (c₁) can change. Determine the range of values of c₁ for which the optimal solution does not change (i.e. we will get the same optimal solution in terms of the variables). For your reference, see the problem below.

A workshop produces two products: chairs ( x ) and tables ( y ):

The profit is c1= 5€ per chair and c2= 10€ per table.