It was really smart of you to ask. Most interviewees are scared to ask such things. I mean it is our right to know how much and what we will get for working on a job. I was like that once but then I learned from my cousin that it's just appropriate and our right to ask for our compensation. If the interviewer gets annoyed by such questions then that just shows how unprofessional he/she is. Nobody in their right minds would go work for a company who doesn't tell their employees how much they will get during the interview including the benefits and allowances.

I had experienced the same thing as you back when I was just looking for a job. I asked them and got annoyed so I simple just went to the flow until the interview ended and never look back nor I am planning to go back in case they call me that I am hired.