A. 10
B. 20
C. 21
D. 111
Answer
Correct Answer: C. 21
Detail about MCQs
To convert the binary number 10101 to its decimal equivalent, you can use the positional notation system. Each digit in a binary number represents a power of 2, starting from the rightmost digit as 2^0, then increasing by one power for each subsequent digit to the left.
So, 10101 in binary is calculated as:
1 * 2^4 + 0 * 2^3 + 1 * 2^2 + 0 * 2^1 + 1 * 2^0 = 16 + 0 + 4 + 0 + 1 = 21
Therefore, the correct answer is:
C. 21