Please help with the following question.

Industrial Designs has been awarded a contract to design a label for a new wine produced by Lake View Winery. The company estimates that 150 hours will be required to complete the project. The rm's three graphic designers available for assignment to this project are Lisa, a senior designer and team leader; David, a senior designer; and Sarah, a junior designer. Because Lisa has worked on several projects for Lake View Winerv, management specied that Lisa must be assigned at least 40% of the total number of hours assigned to the two senior designers. To provide label designing experience for Sarah, the junior designer must be assigned at least 15% of the total project time. However, the number of hours assigned to Sarah must not exceed 25% of the total number of hours assigned to the two senior designers. Due to other project commitments, Lisa has a maximum of 50 hours available to work on this project. Hourly wage rates are $30 for Lisa, $15 for David, and $18 for Sarah. a) Formulate a linear program that can be used to determine the number of hours each graphic designer should be assigned to the project to minimize total cost. If an amount is zero, enter \"0\". If the constant is "1" it must be entered in the box. b) How many hours should be assigned to each graphic designer? c) Suppose Lisa could be assigned more than 50 hours. What e'ect would this have on the optimal solution? Explain. If an amount is zero, enter \"0\". d) If Sarah were not required to work a minimum number of hours on this project, would the optimal solution change