Logically your table should also have a primary key.
If you have it then the below query must work for you
select t1.primarykey, t1.LedgerNumber, t1.LedgerName , t1.Amount
from table1 t1
inner join
(
select LedgerNumber , max(primarykey) primarykey
from table1
group by LedgerNumber
) t2 on t2.primarykey = t1.primarykey