How many letters does the top answer for “being ten more than fifty” have?

The most common answer is lx (2 letters).

Crossword clue: being ten more than fifty

3 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

lx 2 letters wn-def

a unit of illumination equal to 1 lumen per square meter; 0.0929 foot candle

sixty 5 letters wn-def

the cardinal number that is the product of ten and six

threescore 10 letters wn-def

a set with 3 times 20 members

being eight more than fifty 60% similar → lviii

being five more than fifty 60% similar → lv

being one more than fifty 60% similar → li

being one more than ten 60% similar → eleven, xi

being seven more than fifty 60% similar → lvii

being six more than fifty 60% similar → lvi

being ten more than eighty 60% similar → ninety

being ten more than forty 60% similar → fifty