Which number will replace the question mark (?) in the following series: 12, 25, 49, ?, 197, 395

Question

Accepted Answer

Let's analyze the series:

**Given:**  
12, 25, 49, ?, 197, 395

Let's look for a pattern:

### Step 1: Check the differences

- 25 - 12 = 13
- 49 - 25 = 24
- ? - 49 = ?
- 197 - ? = ?
- 395 - 197 = 198

But the differences (13, 24, ?, ?, 198) don't immediately suggest a simple pattern.

---

### Step 2: Check if each term is roughly double the previous

- 12 × 2 = 24 (close to 25)
- 25 × 2 = 50 (close to 49)
- 49 × 2 = 98
- 197 × 2 = 394 (close to 395)

It looks like each term is nearly double the previous term, but either +1 or -1.

Let's check:

- 12 × 2 + 1 = 25
- 25 × 2 - 1 = 49
- 49 × 2 + 1 = 99
- 99 × 2 - 1 = 197
- 197 × 2 + 1 = 395

So the pattern is:  
**Multiply by 2, then alternately add 1 and subtract 1**

---

### Step 3: Fill in the missing number

After 49, the next step should be:

- 49 × 2 + 1 = 99

So, the missing number is **99**.

---

## Final Answer

$$
\boxed{99}
$$

**The missing number in the series is 99.**

Answer

Answer

Answer