How many hexadecimal digits are used to represent a byte, and why is hex commonly used in computing?

• A. Two hex digits per byte; hex is compact and maps cleanly to 4-bit nibbles.
• B. One hex digit per byte; hex is always preferred for speed.
• C. Four hex digits per byte; hex simplifies arithmetic.
• D. Three hex digits per byte; hex aligns with ASCII.

Answer: (A)

A byte is 8 bits, and each hex digit represents 4 bits, so two hex digits are needed to represent a full byte. Hex is popular in computing because it aligns neatly with these 4-bit nibbles, making binary data easier to read, write, and interpret—memory addresses, machine code, and data dumps look cleaner when shown in hex. The other ideas don’t fit: a single hex digit can only represent 4 bits, four hex digits would be 16 bits, and three hex digits would be 12 bits, which doesn’t match a byte. The notion that hex is chosen for speed isn’t accurate; its usefulness is in readability and direct mapping to binary.