Which numeral system uses sixteen distinct symbols, 0-9 and A-F?

• A. Binary
• B. Hexadecimal
• C. Decimal
• D. Octal

Answer: (B)

Hexadecimal uses sixteen distinct symbols: 0 through 9 for values zero to nine, and A through F for values ten to fifteen. Each position represents a power of sixteen, and one hex digit corresponds to four binary bits (since 2^4 = 16), which makes it a compact way to represent binary data. That compact mapping is why hex is widely used in computing—for example, to write bytes (two hex digits per byte) or color codes in web design. The other systems use fewer symbols: binary uses just 0 and 1, decimal uses 0–9, and octal uses 0–7. So the system described by sixteen distinct symbols 0–9 and A–F is hexadecimal.