Countries, US States, Capitals, Elements, 100 Most Common Words: Lowest average letter value (A=1, B=2... Z=26)
You are shown number of letters and 'average'. You are also shown the 'highest' letter contained in the answer (except when it's less than 3 letters long)
For each word you work out the sum of 'letter values' where A=1, B =2... Z=26. Then divide by the number of letters, so you get the 'average letter value'. If this average is, say, 5.4, it corresponds to 'E+' since E is the 5th letter