The hexadecimal number system consists of the symbols

Concept

A positional number system with radix b needs exactly b distinct digit symbols. Each digit represents one value from 0 through b − 1, and place values are powers of the radix.

Application

Hexadecimal has radix 16, so it needs sixteen symbols. The ten numerals 0–9 represent values zero through nine, and A–F represent values ten through fifteen. Therefore its symbol set is 0–9 and A–F.

Contrast

• 0–7 supplies eight symbols, the digit set conventionally used in octal notation.

• 0–7 and A–F supplies fourteen symbols, so two numerical symbols are missing from a sixteen-symbol set.

• “None of these” does not apply because a complete sixteen-symbol set is listed.

Cross-check

Counting gives 10 numeral symbols + 6 letter symbols = 16 symbols, exactly matching radix 16. Thus the hexadecimal symbols are 0–9 and A–F.