You purchase 90 shares for $50 a share ($4,500), and after a year the price falls to $45. Calculate the percentage return on your investment if you bought the stock on margin and the margin requirement was (ignore commissions, dividends, and interest expense):

a) 20 percent. Use a minus sign to enter the amount as a negative value. Round your answer to one decimal place.

_________%

b) 65 percent. Use a minus sign to enter the amount as a negative value. Round your answer to one decimal place.

________%

c) 75 percent. Use a minus sign to enter the amount as a negative value. Round your answer to one decimal place.

________%