a Your company is considering two investments projects each of which requires an up-front expenditure of Sh. 25 million. You estimate the cost of capital is 10% and that the investments will produce cash flows as follows: Year IN 2 3 4 Project A 5,000,000 10,000,000 15,000,000 20,000,000 Project B 20,000,000 10,000,000 8,000,000 6,000,000 Required: i) Calculate the payback period and NPV for each project, (12 marks) ii) Evaluate the viability of the investments assuming they are mutually exclusive