Question

The first three octets of your subnet mask are 255.255.255. The last octet is 11100000. What is the subnet mask?
Group of answer choices

255.255.255.0

255.255.255.128

255.255.255.224

255.0.0.0

Answer 1

To determine the subnet mask from the information provided, we need to convert the last octet, which is given as `11100000` in binary, to decimal.

The binary `11100000` can be broken down as follows:

- The first bit (1) represents 2^7 = 128
- The second bit (1) represents 2^6 = 64
- The third bit (1) represents 2^5 = 32
- The fourth bit (0) represents 2^4 = 0
- The fifth bit (0) represents 2^3 = 0
- The sixth bit (0) represents 2^2 = 0
- The seventh bit (0) represents 2^1 = 0
- The eighth bit (0) represents 2^0 = 0

Adding these values together:
- 128 + 64 + 32 = 224

Thus, the last octet in decimal is `224`. Therefore, the complete subnet mask is:

**255.255.255.224**

So, the correct answer is:

**255.255.255.224**