It was difficult for me to complete the project with Drek because he is one of those persons who think he is always right.
Is the sentence above right?
I think it's not correct since one of those persons is singular. So, we have to use singular verb thinks.
So, the sentence would be
It was difficult for me to complete the project with Drek because he is one of those persons who thinks he is always right.
Am I right about my thinking? Or is it referring to only group of persons?
Consider other sentences like
He was one of those who goes to work by bike.
He was one of those who go to work by bike.
Which sentence is correct grammatically?
Could you please tell me which one who refers to in the sentences and grammar regarding this usage?