Which of the following is an odd composite number?

Options

A. `7`
B. `9`
C. `11`
D. `12`

Answer

To determine which of the following numbers is an odd composite number, we will analyze each option provided: 7, 9, 11, and 12.

### Step 1: Understand the definitions
- **Odd Number**: An odd number is not divisible by 2. This means when you divide it by 2, there is a remainder of 1.
- **Composite Number**: A composite number has more than two factors. This means it can be divided evenly by numbers other than 1 and itself.

### Step 2: Analyze each option

1. **Option 1: 7**
- **Check if it's odd**: 7 is not divisible by 2 (7 ÷ 2 = 3 remainder 1), so it is an odd number.
- **Find factors**: The factors of 7 are 1 and 7. Since it only has two factors, 7 is a prime number, not a composite number.

2. **Option 2: 9**
- **Check if it's odd**: 9 is not divisible by 2 (9 ÷ 2 = 4 remainder 1), so it is an odd number.
- **Find factors**: The factors of 9 are 1, 3, and 9. Since it has more than two factors, 9 is a composite number.

3. **Option 3: 11**
- **Check if it's odd**: 11 is not divisible by 2 (11 ÷ 2 = 5 remainder 1), so it is an odd number.
- **Find factors**: The factors of 11 are 1 and 11. Since it only has two factors, 11 is a prime number, not a composite number.

4. **Option 4: 12**
- **Check if it's odd**: 12 is divisible by 2 (12 ÷ 2 = 6), so it is an even number. Therefore, it cannot be an odd composite number.

### Step 3: Conclusion
After analyzing all the options, the only number that is both odd and composite is **9**.

### Final Answer
The odd composite number among the options is **9**.

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