hassan has recently opened a margin account. He bought 200 shares of stock in the Abington Corporation at S80 per share by paying 70 percent initial margin for the stock, and shortly thereafter received a margin call from his broker. The broker explained that hassan's new account did not meet the maintenance margin requirements of 30 percent because the price of Abington stock fell right after hassan bought it. What percentage decline must Abington experience for hassan to violate the 30 percent maintenance margin requirement?