If a person prays for more than one deceased person, what will his reward be?
Question

                A man prayed one funeral prayer for five deceased persons; will he have one qeeraat (large amount of reward) for each person, or is the number of qeeraats connected to the number of prayers? May Allaah reward you with good.
Praise be to Allah.
    We hope that he will have as many qeeraats as the number of 
    people he prayed for, because the Prophet  (peace and blessings of 
    Allaah be upon him) said: “Whoever prays the funeral prayer will have one 
    qeeraat (of reward), and whoever follows the bier until the deceased is 
    buried will have two qeeraats.” (Narrated by Muslim). And there are other 
    similar ahaadeeth, all of which indicates that the number of qeeraats 
    depends on the number of deceased persons. So whoever prays the funeral 
    prayer for one person will have one qeeraat, and whoever follows the bier 
    until the person is buried will have one qeeraat. Whoever prays the funeral 
    prayer and then follows the bier until the person is buried will have two 
    qeeraats. This is by the bounty of Allaah and His kindness to His slaves; to 
    Him be praise and thanks; there is no god other than Him and no lord besides 
    Him, and Allaah is the source of strength.