NO.PZ2016021706000003
问题如下：
Megan, a student learning corporate finance this year, wrote down something about NPV and IRR on her notebook.
Statement 1: The IRR is the discount rate that makes the project's present value of cash inflows equal to the present value of cash outflows.
Statement 2: Analyst should use the IRRs to select the project, if the IRR method gives a different ranking result from the NPV method.
Statement 3: The NPV is the present value of the future after-tax cash flows minus the investment outlay.
Statement 4: If IRR> the required rate of return, accept the project.
Which of Megan's statements are correct?
选项：
A.Statement 1, 3
B.Statement 1, 3, 4
C.Statement 2, 4
解释：
B is correct.
Statement 2 is incorrect, because the NPV method should be selected if NPV and IRR give conflicting decisions. Statement 1,3,4 are all correct.
这里强调了after tax得，我有点纠结，npv计算里，么有刻意强调过税前税后好像。
这题因为答案得设置，3基本是不用看得，但是如果是1，4和1，3，4对比我就有点纠结。
请问有明确得定义说npv是税后得吗？那么irr也是税后？计算npv得时候，没有说税前税后，都要按税后算吗
