Home » Digital Electronics » Digital Arithmetic Operations and Circuits

Hex subtraction: Compute FC48 − AB91 (hexadecimal). Choose the correct hex result.

Difficulty: Easy

5B77
5267
50B7
5077
4FB7

Correct Answer: 50B7

Explanation:

Introduction / Context:
Hex arithmetic is common in low-level debugging and digital design. Subtracting two 16-bit hex values can be done by column subtraction with borrows or by converting to integers and back.

Given Data / Assumptions:

Operands: FC48 and AB91 (hex).
Unsigned subtraction.

Concept / Approach:
Either convert to decimal and subtract, or perform hex column subtraction: (FC48) − (AB91) = 50B7.

Step-by-Step Solution:

8 − 1 = 7.4 − 9 → borrow: (4+16) − 9 = 11 = B; borrow 1.(C=12) − (B=11) with prior borrow cleared: 12 − 11 = 1, but remember the previous borrow was already applied in the lower nibble; recompute carefully across bytes to confirm final: 0xFC48 − 0xAB91 = 0x50B7.F − A = 5 (after handling intermediate borrows).

Verification / Alternative check:
Integer check: 0xFC48 (64584) − 0xAB91 (43921) = 20663 = 0x50B7.

Why Other Options Are Wrong:

5B77/5267/5077/4FB7: Do not equal the computed difference.

Common Pitfalls:
Dropping a borrow between nibbles or mixing decimal and hex digits.

Hex subtraction: Compute FC48 − AB91 (hexadecimal). Choose the correct hex result.

More Questions from Digital Arithmetic Operations and Circuits

Discussion & Comments