Difficulty: Easy
Correct Answer: 13.625
Explanation:
Introduction / Context:Binary-to-decimal conversion requires positional weighting. Bits left of the point use powers of 2 with nonnegative exponents; bits right of the point use negative exponents. This problem includes both integer and fractional parts, so we convert each separately and then sum.
Given Data / Assumptions:
Concept / Approach:For a binary value b3 b2 b1 b0 . b-1 b-2 b-3, the decimal value is sum(bi * 2^i). Compute integer and fractional contributions independently to avoid mistakes, then add them.
Step-by-Step Solution:
Integer part 1101 = 12^3 + 12^2 + 02^1 + 12^0Compute → 8 + 4 + 0 + 1 = 13Fractional part .101 = 12^-1 + 02^-2 + 12^-3Compute → 10.5 + 00.25 + 10.125 = 0.625Total decimal value = 13 + 0.625 = 13.625Verification / Alternative check:As a quick check, compare nearby options: 13.5 corresponds to .100, 13.75 corresponds to .11 (i.e., .110), and 13.875 corresponds to .111. Our fractional .101 equals 0.625, confirming 13.625.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:13.625
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