The phrase "two sets of questions" is correct and can be used in written English.
It refers to two different groups of questions. Example: The professor handed out two sets of questions for the final exam, each with a different level of difficulty.
When doctors read trials like Ridker's, we generally ask two sets of questions.
Two sets of questions are put forth regarding the relationship between social research and public policy design.
The total pool was split evenly between the two sets of questions, and the surveys we received mimicked this ratio (914 from innovation and 911 from pricing).
The two sets of questions are closely linked in ways that echo the connections between studies of language in general and studies of syntax in general.
As the outcome of the case turned on an interpretation of EC law, the judge stayed the proceedings and referred two sets of questions to the European Court of Justice (the "Court").
This paper draws on the history of irrigation in the US West to address two sets of questions: First, did problems of collective action arise during the development of irrigation in that region?
Here's four sets of questions for Mr Cameron and Ed Miliband to get started.
They can be structured around five sets of questions, part-ethical (what higher education should be seeking to inspire or inculcate in terms of habits of thinking) and part-epistemological (how it validates certain types of knowledge).
They rated the three sets of questions on four measures.
Rodger, I'm going to cheat and give you five sets of questions.
The first three sets of questions of the focus group were developed to explore the constructs of interest and motivation.
