Explain the concept of Payback Period (PP) in capital budgeting, and how it is computed. What is the payback period of a project with the following cashflows (at time periods 0, 1, 2 and 3): -$50,000, $30,000, $15,000, $15,000? Under what circumstances would PP be preferred to the Net Present Value (NPV) approach. (maximum length guide: about 150 words)