How to get first record out of each group from the result retrieved by using group by command

Suppose if Input is:

ID	GROUP ID	QTY
1	1	100
2	1	200
3	1	300
4	2	98
5	2	198
6	3	175
7	3	275
8	3	375
9	4	215

Output should be

ID	GROUP ID	QTY
1	1	100
4	2	98
6	3	175
9	4	215

 Solution:

 Get first record out of each group from the result:

declare @T table (ID int, GroupID int, Qty int)
insert into @T values
(1, 1, 100),
(2, 1, 200),
(3, 1, 300),
(4, 2, 98),
(5, 2, 198),
(6, 3, 175),
(7, 3, 275),
(8, 3, 375),
(9, 4, 215)

;with cte as
(
  select
    ID,
    GroupID,
    Qty,
    rank() over(partition by GroupID order by ID) as rn
  from @T
)  
select ID, GroupID, Qty
from cte
where rn = 1