Interviewers will usually throw in a set or two of purposefully challenging or difficult questions, mostly to inspect an applicant’s ability to handle stressful or problematic situations. On top of the fact it’s already a nerve-wrecking experience, it can be hard to consciously stop the frowns from spreading across your face. Any sort of negative indication you show off will severely damage the impression you had been building with the interviewer, so ensure you handle these questions calmly and competently. Take a moment and never be afraid to politely ask an interviewer to repeat or reword tricky question for you.