What numerical system uses the digits 0-9 and letters A-F?

The system that uses the digits 0-9 and the letters A-F is the hexadecimal system. Hexadecimal is a base-16 number system, which means it encompasses 16 distinct symbols. The digits 0 through 9 represent values zero to nine, while the letters A through F represent values ten to fifteen.

This numeric representation is particularly useful in computing and digital electronics because it provides a more compact way of expressing binary values. Since one hexadecimal digit can represent four binary digits (or bits), it simplifies the representation of large binary numbers, making it easier to read and understand for humans.

The other numerical systems mentioned—binary, decimal, and octal—use different sets of symbols. Binary utilizes only the digits 0 and 1, decimal employs the digits 0-9, and octal uses digits 0-7. None of these include the letters A-F, which distinguishes hexadecimal as the correct answer.