thanks sergey for your help,done my work with these codes.

CAST(SUM(IIF(res23="Fail",1,0)) AS I)	res23,;

i want convert my these codes to get percentage(%)

dis4 = c/100
 dis5 = Round(a/dis4, 2)
 dis = Alltrim(Str(dis5, 12, 2))+"%"
 cperc=dis

how it will be done in sql