Difficulty: Easy
Correct Answer: 154
Explanation:
Introduction / Context:Binary-to-decimal conversion is a fundamental skill in digital electronics and computer science. Each binary digit (bit) represents a power of 2, and the decimal value is the sum of those powers where bits are 1.
Given Data / Assumptions:
Concept / Approach:For a binary string b7 b6 b5 b4 b3 b2 b1 b0, the decimal value is sum(bi * 2^i) for i from 0 to 7. Only positions with bi = 1 contribute to the sum.
Step-by-Step Solution:
1) Write place values: 2^7=128, 2^6=64, 2^5=32, 2^4=16, 2^3=8, 2^2=4, 2^1=2, 2^0=1.2) Map bits (10011010): 1·128 + 0·64 + 0·32 + 1·16 + 1·8 + 0·4 + 1·2 + 0·1.3) Sum contributions: 128 + 16 + 8 + 2 = 154.4) Therefore, decimal value = 154.Verification / Alternative check:Group into nibbles: 1001 1010 → 0x9A in hex. Hex 0x9A = 9*16 + 10 = 144 + 10 = 154, confirming the result.
Why Other Options Are Wrong:
Common Pitfalls:Forgetting that the leftmost bit is the highest power of 2, or mixing up 2^3=8 and 2^4=16.
Final Answer:154
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