I was practicing for the SAT a couple days ago and one question was asking whether to correct the phrase "one of the legislators who are going" or leave it the same. I chose to change the phrase to "one of the legislators who is going." However, the book said that the answer was to keep the phrase as "one of the legislators who are going."
Does anyone know which answer is correct? I was positive I had the right answer until I saw what the book said.
Also, there was a math problem in the book that forgot about negative numbers. I thought that was amusing.
Since "of the legislators" is a prepositional phrase, making "legislators" an object, I tend to agree with you. Normally, prepositional phrases don't affect the verb. "Who" should refer to a nomitive or subjective, in this case, "one." However, according to Elements of Style, "who" is the beginning of a relative phrase and the subject is legislators. So, use the plural verb form.
About test booklets...we have noted numerous, too many, errors.