I have a feeling that some of the other teachers might disagree, but I would answer thus:
The majority of people are poor.
This is grammatically incorrect because I understand that The majority of people is a singular noun phrase, and according to the rules of grammar, you should get:
The majority of people is poor.
However, the former sentence is not only natural but probably more common than the second, and certainly conforms to Standard English. I personally would use the former.
Student or Learner