A Question from Manhattan GMAT-SC-Subject Verb Agreement

[zoha.zargham]

15) A majority of railway commuters reads or listens to music while traveling.

Does the verb agree with the subject?
According to the strategy guild :
Some numerical words such as majority and minority can be either singular or plural depending on their context.

base on the above statement I concluded that the right form of verb should be "READ" and "LISTEN" because of the word commuters. However, on the answer key it was "READS" & "LISTENS"

Your help is much appreciated

[apurva.std]

A majority/minority is depends on usage.
The majority of students ARE hard worker.
The student majority IS opposed to reservation.

In first, we are taking abt students but in later its one unit.
so in the question posted, it will come as read...and listen

hope this is clear..