Insert the missing number-
5, 12, 9, 16, 13, 20, …….

Options

A. 27
B. 23
C. 17
D. None of these

Answer

To find the missing number in the series: 5, 12, 9, 16, 13, 20, …, we will analyze the pattern in the series step by step.

### Step-by-Step Solution:

1. **Identify the Pattern:**
- The series alternates between adding 7 and subtracting 3.
- Let's break down the series:
- Start with 5.
- Add 7: \( 5 + 7 = 12 \)
- Subtract 3: \( 12 - 3 = 9 \)
- Add 7: \( 9 + 7 = 16 \)
- Subtract 3: \( 16 - 3 = 13 \)
- Add 7: \( 13 + 7 = 20 \)

2. **Continue the Pattern:**
- Now, following the established pattern, after 20, we will subtract 3:
- \( 20 - 3 = 17 \)

3. **Conclusion:**
- The missing number in the series is 17.

### Final Answer:
The missing number is **17**.