Margin Trading (show work)

An investor opens her first brokerage account, and purchases 500 shares of Cisco shares at $24 per share. She borrows $5,000 from her broker to help pay for the purchase. The interest rate of the loan is 3.5%.

a)What is the initial margin in her account when she first purchases the stock?

b)If the price falls to $20 per share by the end of the year, what is the remaining margin in her account? If the maintenance margin requirement is 35%, will she receive a margin call?

c)What is the rate of return on the investment if she sells the shares at the end of the year at $20 per share?