from the beginning to the end of 2007 , the price of a stock rose 20 percent . in 2008 , it dropped 25 percent . in 2009 , it rose 25 percent . what percent of the stock â € ™ s 2007 starting price was the price of the stock at the end of 2009 ?
"assume a value at the beginning of 2007 . as this is a % question , assume p = 100 . at the end of 2007 it becmae = 1.2 * 100 = 120 at the end of 2008 it decreased by 25 % = 120 * . 75 = 90 at the end of 2009 it increased by 25 % = 90 * 1.25 = 112.5 thus ratio = 112.5 / 100 = 1.125 ( in % terms = 12.5 % ) . thus e is the correct answer ."
multiply(multiply(multiply(const_100, divide(add(const_100, 20), const_100)), divide(subtract(const_100, 25), const_100)), divide(add(const_100, 25), const_100))