Where the FTSE 100 is trading today

Roughly what level is the FTSE 100 index at right now?

Know the current level to within a few per cent before the interview. The FTSE 100 is the main UK large-cap equity index; check its level, recent trend and the main drivers (e.g. commodity and bank stocks, sterling) in the days before. The interviewer is testing whether you follow markets, so a confident approximate figure plus some context beats an exact number with no understanding.