请问老师，第17题，为什么不能用已知的一天的mean和standard deviation 去计算一天的var，再乘以10天呢？

DERIVATIVES中 这道题C选项 ***老师视频中说的解释我没懂

老师，我发现有些题目用后面－前面／前面可是有些又是用后面－前面／后面，这个怎么区分啊？

投资了100万无形资产，5年摊销，会计记帐如下：第一年 asset 中cash 降低100，同时无形资产增加80万，equity 中retained earning（armotization) 降低20万。 第二年：asset 无形资产降低20万，equity retained earning(armotization) 降低20万。 这样记账对否？谢谢。

财务分析里rent为什么算SG&A不算COGS? 租用厂房不是和生产直接相关么？还有utility,生产车间的电费不是也和生产直接相关么？谢谢

FAR合成，下面分解的第一部分long270天的是买入的现金还是合约

55-34请讲解

55-42这道题根据排除法得到了正确答案C，但是根据已知条件结合课后答案，没看出来这个指标具体的代入数字是怎么得来的，请解答

12. Trumpit Resorts Company currently has 1.2 million common shares of stock outstanding and the stock has a beta of 2.2. It also has $10 million face value of bonds that have five years remaining to maturity and 8 percent coupon with semi-annual payments, and are priced to yield 13.65 percent. If Trumpit issues up to $2.5 million of new bonds, the bonds will be priced at par and have a yield of 13.65 percent; if it issues bonds beyond $2.5 million, the expected yield on the entire issuance will be 16 percent.。Trumpit has learned that it can issue new common stock at $10 a share. The current risk-free rate of interest is 3 percent and the expected market return is 10 percent. Trumpit’s marginal tax rate is 30 percent. If Trumpit raises $7.5 million of new capital while maintaining the same debt-to-equity ratio, its weighted average cost of capital is closest to: A. 14.5 percent. B. 15.5 percent. C. 16.5 percent. 麻烦老师帮忙讲解一下，谢谢！

8. The Gearing Company has an after-tax cost of debt capital of 4 percent, a cost of preferred stock of 8 percent, a cost of equity capital of 10 percent, and a weighted average cost of capital of 7 percent. Gearing intends to maintain its current capital structure as it raises additional capital. In making its capital-budgeting decisions for the average-risk project, the relevant cost of capital is: A. 4 percent. B. 7 percent. C. 8 percent. 麻烦老师讲解一下，谢谢！