Question 322 of 480
What is the decimal equivalent of the binary number 101101?
Correct Answer:
A
Explanation
To find the decimal equivalent of the binary number 101101, we will break down the process step-by-step.
### Step 1: Understanding Binary Numbers
Binary numbers are base-2 numbers, which means they only use two digits: 0 and 1. Each digit in a binary number represents a power of 2, starting from the rightmost digit, which represents \(2^0\).
### Step 2: Write Down the Binary Number
The binary number we have is **101101**. We will label each digit with its corresponding power of 2:
- The rightmost digit (1) is in the \(2^0\) place.
- The next digit (0) is in the \(2^1\) place.
- The next digit (1) is in the \(2^2\) place.
- The next digit (1) is in the \(2^3\) place.
- The next digit (0) is in the \(2^4\) place.
- The leftmost digit (1) is in the \(2^5\) place.
So, we can represent the binary number as follows:
\[
1 \cdot 2^5 + 0 \cdot 2^4 + 1 \cdot 2^3 + 1 \cdot 2^2 + 0 \cdot 2^1 + 1 \cdot 2^0
\]
### Step 3: Calculate Each Term
Now, we will calculate the value of each term:
- \(1 \cdot 2^5 = 1 \cdot 32 = 32\)
- \(0 \cdot 2^4 = 0 \cdot 16 = 0\)
- \(1 \cdot 2^3 = 1 \cdot 8 = 8\)
- \(1 \cdot 2^2 = 1 \cdot 4 = 4\)
- \(0 \cdot 2^1 = 0 \cdot 2 = 0\)
- \(1 \cdot 2^0 = 1 \cdot 1 = 1\)
### Step 4: Add the Values Together
Now, we will add all these values together:
\[
32 + 0 + 8 + 4 + 0 + 1 = 45
\]
### Conclusion
The decimal equivalent of the binary number **101101** is **45**.
### Explanation of Other Options
Now, let's analyze the other options to understand why they are incorrect:
- **Option B: 22**
- If we were to convert 22 back to binary, it would be 10110, which does not match our original binary number of 101101.
- **Option C: 27**
- The binary representation of 27 is 11011, which again does not match 101101.
- **Option D: 53**
- The binary representation of 53 is 110101, which is also different from 101101.
### Revision Summary
- Binary numbers are base-2 and each digit represents a power of 2.
- To convert binary to decimal, multiply each digit by its corresponding power of 2 and sum the results.
- The binary number 101101 converts to decimal as follows: \(1 \cdot 32 + 0 \cdot 16 + 1 \cdot 8 + 1 \cdot 4 + 0 \cdot 2 + 1 \cdot 1 = 45\).
- The correct answer is **A. 45**; other options do not match the binary number provided.