问道Option定价的题，跪求牛人解答！！！ 江湖救急啊

教授给的一道难题，哪位大哥能帮忙解决了 ~~~~~小弟感激不尽~~

A firm has assets of $100 and 5-year-to-maturity zero-coupon debt with a
face value of $150. Assume that investment projects have the same volatility as
existing assets. Also assume that the volatility of the assets is 30% and that the
riskless rate is 8%. Finally, assume that the firm makes no payouts prior to the
maturity date of the debt.
a. The firm is considering an investment project costing $1. What is the amount
by which the project’s value must exceed its cost in order for shareholders to
be willing to pay for it? Repeat for project values of $10 and $25.
b. Now suppose the firm finances the project by issuing debt that has lower
priority than existing debt. How much must a $1, $10, or $25 project be
worth if the shareholders are willing to fund it?

(Hint for Problem : The equity holders will do a project if it increases their
option value. They have a call with value now. If they do a project they give up
this call and get another call.)

是我的问题太简单了还是没人会？ 各位finance的 phd帮帮忙啊 ，我就知望着这道题了

All you need is a BS spread-sheet.

居然是 TONY神牛来解答。。。。。。一头汗啊 。。。。。杀鸡沿用牛刀。。。

ANYWAY,很感谢。。。