Question:i can't figure out if you only need 2 decision variables (X1 = number of chairs, X2 = number of tables)

Vicky's manufactures chairs and tables. Each chair or table must go through the painting shop and assembly shop. If the painting shop were completely devoted to painting chairs, 900 per day could be painted, whereas if it were completely devoted to painting tables, 500 per day could be painted. If the assemly shop were completely devoted to assemble the chairs, 1500 can be assembled, whereas if it were completely devoted to assemble the tables, 1100 per day can be assembled. Each chair brings a profit of 110 and each table brings a profit of 160. Formulate an LP to maximize vicky's profit. *Note, don't have to solve the LP, just define the decision variables, state the objective function and the constraints.*

or 4 variables (X1= number of chairs painted , X2 = number of tables painted ,X3 = number of chairs assembled, X2 = number of tables assembled.)

and other than the obvious constraints X1 <= 900, X2 <= 500 , X3 <= 1500, X4 <= 1100 i can't see how they help .

Any help would be greatly appreciated.