FC0-U71 Tech Concepts and Terminology Practice Question
Which of the following is the result of the binary operation 1101 AND 1011?
⚠ Common exam trap
It's easy for candidates to confuse AND with OR — candidates who see two binary numbers and mentally 'combine' them often produce the OR result (1111) instead of the AND result (1001).
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
1001
The AND operation compares each bit position and outputs 1 only when both input bits are 1. Aligning 1101 and 1011: bit1 1&1=1, bit2 1&0=0, bit3 0&1=0, bit4 1&1=1, giving 1001. This matches option D.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
1111
Why it's wrong here
AND outputs 1 only where both operands hold 1, so 1101 AND 1011 gives 1001, not 1111. A result of all ones requires both operands to be 1111; 1111 is what bitwise OR of these two values would produce.
- ✗
1011
Why it's wrong here
Bitwise AND compares each column and yields 1 only where both bits are 1: 1101 AND 1011 gives 1001. Returning 1011 simply echoes the second operand, which would require OR, since 1101 OR 1011 equals 1111, not 1011.
- ✗
1101
Why it's wrong here
Bitwise AND compares each column and outputs 1 only where both bits are 1; 1101 AND 1011 yields 1001, not 1101. The value 1101 is simply the first operand copied unchanged, which would only occur if the second operand were all ones.
- ✓
1001
Why this is correct
Bitwise AND compares each column, outputting 1 only where both bits are 1. Aligning 1101 with 1011: the first, third and fourth columns yield 1, while the second yields 0, giving 1001. This satisfies the stem's requirement for the result of the AND operation.
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Same concept, more angles
5 more ways this is tested on FC0-U71
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Which of the following is the decimal equivalent of the binary number 1101?
easy- ✓ A.13
- B.10
- C.14
- D.11
Why A: Binary 1101 converts to decimal by summing the place values where bits are 1: (1×8) + (1×4) + (0×2) + (1×1) = 8 + 4 + 0 + 1 = 13. Therefore the decimal equivalent is 13.
Variation 2. Which of the following is the binary representation of the decimal number 10?
easy- A.1000
- ✓ B.1010
- C.1100
- D.1110
Why B: Decimal 10 in binary is 1010. The place values from right to left are 1, 2, 4, 8; 8 + 2 = 10, so bits 3 and 1 are set (1010). This is a straightforward base-2 conversion.
Variation 3. What is the decimal equivalent of the binary number 1101?
easy- A.15
- ✓ B.13
- C.10
- D.12
Why B: The binary number 1101 has four bits: the leftmost bit is the 8's place (2^3), then 4's (2^2), 2's (2^1), and 1's (2^0). Adding the values where bits are 1: 8 + 4 + 0 + 1 = 13. Therefore, the decimal equivalent is 13.
Variation 4. Which of the following is the binary representation of the decimal number 5?
easy- A.0100
- B.0011
- C.0110
- ✓ D.0101
Why D: The decimal number 5 in binary is 0101, because 4 (2^2) + 1 (2^0) = 5. Reading the bits left to right as 8-4-2-1 place values: 0*8 + 1*4 + 0*2 + 1*1 = 5. This is the correct 4-bit binary representation of decimal 5.
Variation 5. A technician is converting the decimal number 255 to binary. Which binary value is correct?
medium- A.10000000
- B.11111110
- C.1111111
- ✓ D.11111111
Why D: 255 in binary is 11111111 (eight 1s).
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This FC0-U71 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the FC0-U71 exam.