In your spreadsheet, change the capacity to 250 in the capacity constraint, the regular demand to 150, and the discount demand to 150. Then re-solve the model.
What is the objective value of the optimal solution?
You can change the values in the capacity constraint RHS (cell D11), the regular demand (cell D5), and the discount demand (cell D6) and resolve the model by selecting “Solver…” in the “Tools” menu. After it finishes solving, the objective value can be found in the blue cell (B8)