A food production facility produces chocolate, biscuit, and cake. The three main ingredients of each product are milk, sugar and flour. The amounts of the ingredients for each unit of product are indicated in the following table including the profit per unit of the products. Milk (lt) Sugar (kg) Flour (kg) Profit Chocolate (unit) 0.3 0.3 0.1 $0.75 Biscuit (unit) 0.2 0.4 0.3 $0.95 Cake (unit) 0.3 0.2 0.5 $1.2 The maximum capacity of the facility is to use 4,500 liters of milk, 4,000 kilograms of sugar, and 5,000 kilograms of flour. The facility manager states that the amount of biscuits produced cannot exceed the half amount of chocolate produced. Furthermore, the amount of cake produced is required to be at most the sum of the amount of chocolate and biscuit produced. Formulate this problem as an LP model to maximize total profit