buying margin cara has brokerage account she wants to purchase 200 shares of Stock x at $30 per share. she has available capital is $8,000. she ask her broker for a brokers call with the interest rate on the loan at 5% per year. Assume the interest payment happens at the end of the year.

a. What is the percentage margin in her account when she first purchased the 200 shares?

b. If stock price falls to $20 per share by the end of the year, what is the remaining margin in her account

c.). Suppose price drops to $20 per share at the end of the year, what is your total rate of return of her investment?