How to use MySQL 'RAND()' with limit in with Zend Select Query

  We need to use new Zend_Db_Expr('RAND()') with select query
  Ex: $selectQry    =    $this->util->db->select()->from(array('P'=>$this->_name),array('package_id','name','day_duration','night_duration','price','discount_price'))
                                                    ->order(new Zend_Db_Expr('RAND()'))
                                                    ->limit(2);