Payback, NPV, and MIRR

Your division is considering two investment projects, each of which requires an up-front expenditure of $25 million. You estimate that the cost of capital is 10% and that the investments will produce the following after-tax cash flows (in millions of dollars):

Year	Project A	Project B
1	5	20
2	10	10
3	15	8
4	20	6

What is the regular payback period for each of the projects?

Answer: A = 2.67 years; B = 1.5 years.

Suppose the upfront expenditure is $23 million.

What is the regular payback period for Project A?