An investment costs $1,688 and pays $150 in perpetuity with the first cash flow coming at the end of each year. If the interest rate is 9% annually, what is the NPV? Solution NPV= Present value of calshflow for perpetuity- Current investment = ($150/0.09)-$1688 = $ 1,666.67-$1688 = ($1.33) 1,666.67.