Hey could someone help solve this problem and show the work so i can learn how its done for tbe future! I need parts 1-3 answered for this

Three years ago, you founded your own company. You invested $120,000 of your own money and received 6.0 million shares of Series A preferred stock. Your company has since been through three additional rounds of financing. Based on the information provided above (and that each share of all series of preferred stock is convertible into one share of common stock), what fractions of the firm do the Series B, C, and D investors each own in your firm? Series B investors own (Round to three decimal places.)