The phrase "into three questions" is correct and can be used in written English
For example: I divided the survey into three questions for the participants to answer.
Let's break down the issue into three questions: Should the United States have a systemic-risk regulator?
"Forgive my grammar, but you have to filter into three questions: 'What do we know, what do we don't know, and when do we expect to know more?' Everything is preliminary, everything can change, but you can't just wait.
Rather, the justification for the war is best addressed by dividing it into three questions: 1) Were there good grounds to threaten Mr Hussein with an imminent military attack if he did not comply with United Nations resolutions?
But the decision can be eased by breaking it down into three questions: Which clinical field(s) should I choose?
Thus we converted the three attributes within Davis's Technology Acceptance Model that we were able to test - perceived usefulness, perceived ease of use and compatibility - into three questions (one of which included seven sub-questions, representing the important contextual influences), which are shown in Table 1.
We divided the 120 items into three question sets, taking into account the balance of the combinations and parts-of-speech of the target words.
A clear opportunity, you might think, for pundits to get stuck into two questions.
It even broke it down into seven questions to help give responses some structure (See http://tinyurl.com/eblp2).
During oral argument he said, "I think in terms of the tax power, I think it's useful to separate this into two questions.
Two "what is" questions asked about a process, so they were each split into four questions with the four annotations (structure, behavior-1, behavior-2, and function).
Recent advances in the estimation of prokaryotic diversity have brought us insight into two questions: what is the extent of prokaryotic diversity, and perhaps more importantly, why bother finding out.
