You purchased shares of Broussard Company using 50 percent margin; you invested a total of $20,000 (buying 1,000 shares at a price of $20 per share) by using $10,000 of your own funds and borrowing $10,000. Determine your percentage profit or loss under the following situations (ignore borrowing costs, dividends, and taxes). In addition, what would the percentage profit and loss be in these scenarios if margin were not used?

1. the stock price rises to $23 a share
2. the stock price rises to $30 a share
3. the stock price falls to $16 a share
4. the stock price falls to $10 a share