whats the solution

Question 3 (Problem Set 3.7) Old Economy Traders opened an account to short sell 1,000 shares of Internet Dreams from the previous problem. The initial margin requirement was 50%. (The margin account pays no interest.) A year later, the price of Internet Dreams has risen from $40 to $50, and the stock has paid a dividend of $2 per share. (a) What is the remaining margin (in dollar amount) in the account a year later? (b) If the maintenance margin requirement is 30%, will Old Economy receive a margin call? (c) What is the rate of return on the investment