FC0-U71 Tech Concepts and Terminology Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  10000000

  Why it's wrong here

  10000000 equals 128, not 255, since only the most significant bit is set. It is tempting because it is the eight-bit value with the highest single bit, which people confuse with the maximum. The stem needs every bit set, giving 11111111.

• ✗

  11111110

  Why it's wrong here

  11111110 equals 254, since the least significant bit is zero; 255 needs all eight bits set to one. This value is the correct answer when converting 254, a common off-by-one trap, but the stem specifies 255.

• ✗

  1111111

  Why it's wrong here

  Seven bits cannot represent 255; the maximum with seven bits is 127. The stem requires eight bits, where 255 is 11111111. It is tempting because 1111111 looks like 'all ones', which people associate with the maximum value, but the bit count is short by one.

• ✓

  11111111

  Why this is correct

  255 equals 2⁸ − 1, so every bit in an 8-bit octet is set. Converting by repeated division by 2 yields remainders of 1 at each step, giving eight ones: 11111111. This satisfies the stem's requirement for the binary representation of the maximum 8-bit decimal value.