If an Imaam stood to add a fifth Rak`ah and the Ma`moomeen(those praying behind the Imaam) were split into: 1-a group which is certain that he had performed four Rak`ahs, and remained sitting until they offered Tasleem with him.2-a group which is certain that he had performed four Rak`ahs, but followed him in performing a fifth Rak`ah.3-a group which is uncertain or arrived late and followed the Imaam. Which group is right?
