4:A company manufactures and sells two models of lamps, L1 and L2. To manufacture each lamp, the manual work involved in model L1 is 20 minutes and for L2, 30 minutes. The mechanical (machine) work involved for L1 is 20 minutes and for L2, 10 minutes. The manual work available per month is 100 hours and the machine is limited to only 80 hours per month. Knowing that the profit per unit is10 for L1 and 15 for L2, respectively, determine the quantities of each lamp that should be manufactured to obtain the maximum benefit.

5) Needed to solve the following LPP using simplex method:

\f