1) Some signboards and sheets are going to be produced in two mechanical workshops of a manufacturing unit. Because of the precautions of job security, 11t workshop may be used up to 20 hours and 2nd workshop may be used up to 16 hours in a day. The table below gives the required information about the problem. a) Formulate an LP model to determine the daily production plan to maximize the profit. Please explain the decision variable and indicate of the model clearly b) Find the dual of the LP model which is established above