Is it appropriate to ask how many candidates are being interviewed?
It's OK to ask an interviewer how many other people are up for the same position. After all, you just want to know the odds you're up against, as anyone would. But even if inquiring is harmless, the way you ask your question might bother the interviewer.
How many candidates make it to the panel interview?
What is a Panel Interview? Panel interviews are interviews at which multiple interviewers are present. Panels typically consist of two to five people, though in some instances there may be more. There's often one person who “leads” the interview, though all who are present are important.
What should you not do in a panel interview?