问题如下：
Company M is financed with $20 million debt and $80 million equity. The management wants to borrow another $10 million debt to repurchase the common shares of the same amount. What`s the WACC after the repurchase?
Relevant information regarding the cost of capital is shown in the above table. The tax rate is 30%.
选项：
A.8.90%
B.8.77%
C.8.61%
解释：
C is correct.
考点：Summary of Capital Structure Theories
解析：回购结束后，公司的资本结构变成Wd=30%，We=70%，WACC = 30%*6.0%*(1-30%) + 70%*10.5% = 8.61%.
在这一知识点讲义例题中，李老师拓展了一下，增发债务产生的利息有税盾作用，税盾带来的好处是归属于股东的，因此我认为equity不应该直接增加10m，而是10+10*30%=83才对，但是这样的话这题就没有答案了。
