[home work ]can any one rewrite this query with out using over partition function but i should get sme result

set nocount on
SET STATISTICS TIME  on
SELECT  [TM_User].[FullName],
        [a].[end_date] as Last_Task_Completion_Date,
        [a].[allocated_hrs]
FROM
  [dbo].[TM_User]
INNER JOIN
(
    SELECT [Task].[task_id] ,
           [Task_Hours].[user_id] ,
           [allocated_hrs],
           ROW_NUMBER() OVER ( PARTITION BY [user_id] ORDER BY [Task].[end_date] DESC ) rtt ,
           [Task].[end_date]
    FROM
    [dbo].[Task_Hours]

    INNER JOIN

   [dbo].[Task] ON [Task].[task_id] = [Task_Hours].[task_id]
   AND allocated_hrs=0
   AND CONVERT(varchar,Task.end_date,111) >= '2013/08/15'
   AND CONVERT(varchar,Task.end_date,111) <='2013/08/29'

) a ON [TM_User].[TM_UserID] = [a].[user_id]

WHERE [a].[rtt] = 1
AND [is_active]= 1


SET STATISTICS TIME  off
set nocount off