According to state wise Males and Females Count 

select Ma.state,Ma.Male,Fa.FeMale from((select distinct(state),count(gender) as Male from tbl_stud where gender='M' group by state)Ma full outer join(select distinct(state),count(gender) as FeMale from tbl_stud where gender='F' group by state)Fa on Ma.state=Fa.state and Ma.state is not null)

No Of Students Attended for Each Subject

select ename,count(stuid) as count from tbl_exams a join tbl_Eresult b on a.eid=b.eid group by ename