Which of the following is not a perfect square ?

Options

A. 12544
B. 3136
C. 23832
D. 1296

Explanation

To determine which of the given numbers is not a perfect square, we can analyze the last digits of each option. A perfect square can only end in certain digits: 0, 1, 4, 5, 6, or 9. The digits that cannot be the last digit of a perfect square are 2, 3, 7, and 8.

Let's evaluate each option:

1. **Option 1: 12,544**
- Last digit: 4
- Since 4 is a possible last digit of a perfect square, we cannot conclude yet.

2. **Option 2: 3,136**
- Last digit: 6
- Since 6 is also a possible last digit of a perfect square, we cannot conclude yet.

3. **Option 3: 23,832**
- Last digit: 2
- Since 2 is not a possible last digit of a perfect square, this number cannot be a perfect square.

4. **Option 4: 12,996**
- Last digit: 6
- Since 6 is a possible last digit of a perfect square, we cannot conclude yet.

Based on the analysis, the number that is not a perfect square is **Option 3: 23,832**.

### Step-by-Step Solution:
1. Identify the last digit of each option.
2. Determine which last digits can be perfect squares (0, 1, 4, 5, 6, 9).
3. Identify which last digits cannot be perfect squares (2, 3, 7, 8).
4. Conclude that the number with a last digit of 2 (Option 3: 23,832) is not a perfect square.