问题如下：
Wilson Flannery is concerned that this project has multiple IRRs.
How many discount rates produce a zero NPV for this project?
选项：
A.One, a discount rate of 0 percent.
B.Two, discount rates of 0 percent and 32 percent.
C.Two, discount rates of 0 percent and 62 percent.
解释：
C is correct.
Discount rates of 0 percent and approximately 61.8 percent both give a zero NPV.
为什么0是一个折现率？
另外一个折现率产生在哪里？cash flow为0和-50那里？这个折现率是怎么算出来的？假定初始值为0，-50折线到0时刻吗？
