Which base uses digits 0-9 and letters A-F to represent numbers from 0 to 15?

Which base uses digits 0-9 and letters A-F to represent numbers from 0 to 15?

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

Answer: (B)

This question tests which numeral system provides a single-character symbol for each value from 0 to 15. To do that, you need 16 distinct symbols. Decimal uses only digits 0–9, so values 10–15 would require more than one digit. Binary uses only 0 and 1, so it has far fewer symbols. Octal uses digits 0–7, which again isn’t enough for 0–15 with one symbol each. Hexadecimal fills the gap by using 16 symbols: 0–9 for values 0–9 and A–F for values 10–15. With these, every value from 0 to 15 has its own single-character representation. This base is also convenient in computing because each hex digit corresponds to four bits, making it easy to map to binary data.

This question tests which numeral system provides a single-character symbol for each value from 0 to 15. To do that, you need 16 distinct symbols. Decimal uses only digits 0–9, so values 10–15 would require more than one digit. Binary uses only 0 and 1, so it has far fewer symbols. Octal uses digits 0–7, which again isn’t enough for 0–15 with one symbol each. Hexadecimal fills the gap by using 16 symbols: 0–9 for values 0–9 and A–F for values 10–15. With these, every value from 0 to 15 has its own single-character representation. This base is also convenient in computing because each hex digit corresponds to four bits, making it easy to map to binary data.