please make the steps clear with the rules, thankyou :)

Example 4-1: Best Efforts vs. Firm Commitment Securities Offering I. firm commitment basis An investment bank agrees to underwrite an issue of 20 million shares of stock for Murray Construction Corp. on a firm commitment basis. The investment bank pays $15.50 per share to Murray Construction Corp. for the 20 million shares of stock. (1) It then sells those shares to the public for $16.35 per share. How much money does Murray Construction Corp. receive? What is the profit to the investment bank? (2) If the investment bank can sell the shares for only $14.75, how much money does Murray Construction Corp. receive? What is the profit to the investment bank? II. best-efforts basis (1) Suppose, instead, that the investment bank agrees to underwrite the 20 million shares on a best-efforts basis. The investment bank is able to sell 18.4 million shares for $15.50 per share, and it charges Murray Construction Corp. $0.375 per share sold. How much money does Murray Construction Corp. receive? What is the profit to the investment bank? (2) If the investment bank can sell the shares for only $14.75, how much money does Murray Construction Corp. receive? What is the profit to the investment bank