Five bottles each hold 10 millilitres of syrup. What is the mean amount of syrup per bottle?

Explanation

The five amounts total 50 millilitres, and dividing by the 5 bottles gives a mean of 10 millilitres, the amount every bottle already holds. Reporting 50 millilitres stops at the combined total and skips the division, so it describes all five bottles together rather than one typical bottle.