My way is very similare to Dwain's way, but I also added the distinct key word so there will be only 2 rows. I also didn't use the stuff function:

DECLARE @Tbl TABLE (Gender char(6), Name varchar(20), Age tinyint)

INSERT INTO @Tbl (Gender, Name, Age)

SELECT 'Male', 'John', 52

UNION ALL

SELECT 'Female', 'Joe', 33

UNION ALL

SELECT 'Male', 'Jim', 42

select distinct Gender,

cast((select Name + ' ' + cast(Age as char(2)) + ' ' FROM @Tbl t1 where t1.Gender = t2.Gender for xml path('')) as varchar(max)) as Det

from @Tbl t2

Adi