In each of the following questions, four numbers are given. Out of these three are alike in some way but rest one is different. Choose the one which is different from the other.

Options

A. 15
B. 63
C. 143
D. 257

Answer

To solve the problem of identifying the odd number out from the given options, we need to analyze the nature of each number (whether they are composite or prime).

### Step-by-Step Solution:

1. **Identify the Numbers**: The four numbers given are:
- Option 1: 15
- Option 2: 63
- Option 3: 143
- Option 4: 257

2. **Determine the Factors of Each Number**:
- **Option 1: 15**
- Factors: 1, 3, 5, 15
- Since it has more than two factors, 15 is a composite number.

- **Option 2: 63**
- Factors: 1, 3, 7, 9, 21, 63
- Since it has more than two factors, 63 is also a composite number.

- **Option 3: 143**
- Factors: 1, 11, 13, 143
- Since it has more than two factors, 143 is a composite number.

- **Option 4: 257**
- Factors: 1, 257
- Since it has only two factors (1 and itself), 257 is a prime number.

3. **Classify the Numbers**:
- Composite Numbers: 15, 63, 143
- Prime Number: 257

4. **Identify the Odd One Out**:
- The first three numbers (15, 63, 143) are composite numbers, while 257 is a prime number.

5. **Conclusion**:
- The number that is different from the others is **Option 4: 257**.

### Final Answer:
The number that is different from the others is **257**.