a) A manufacturer produces two products Crisps and Chips. Chips has a contribution of Kshs. 3 per unit and Chips Kshs. 4 per unit. The manufacturer wishes to establish the weekly production plan which maximises contribution. Production data are as follows: - Crisps Chips Total Available per Week Matching (Hours) 4 2 100 Per Unit Labour (Hours) Materials (Kg) 1 1 4 6 180 40 Because of a trade agreement sale of Crisps are limited to a weekly maximum of 20 units and to honour an agreement with an old established customer at least 10 units of Chips must be sold per week. Use graphical linear programming solution. (7 Marks) a) Outline and discuss the limitations and benefits of PERT and CPM. (4 Marks) b) Enumerate and discuss the application for PERT and CPM. (4 Marks)