问题如下图：
选项：
A. 
B. 
C. 
解释：
老师请问小于12.06%可以很清楚看出，但大于9%是怎么得来的？
NO.PZ2018062005000013 between 9% an12.06% between 12.06% an14.78% B is correct. The question is more obvious to NPV profiles. When cost of capitis 9%, ProjeB is superior to ProjeA baseon NPV rules (428>255). e to 14.78%>12.06%, ProjeA is superior to ProjeB when cost of capitis larger th12.06%. Therefore, the crossover rate of ProjeA anB is between 9% an12.06%.小于12.06能理解，为啥大于9还是不清楚。如果两个设联立方程式求解后与9比较要怎么做？
9% 的时候 B NPV 是 428？ 255？
这道题目画图，纵轴可以直接画成NPV吗
