can you give me the exact formulas for solving these questions? I also would greatly appreciate it if you could put in the numbers in the formula

Samantha Smith believes Thompson will have to grant generous stock options in addition to the salaries projected in his business plan. From experience, she thinks management should have the ability to own at least a 15% share of the company in the form of options by the end of year 5.

What share of the company should Samantha insist on today if the option pool is created AFTER her investment and her required rate of return is 50%?

What share of the company should she insist on if the option pool is allocated BEFORE her investment?