In each of the following number series , a wrong number is given ,find out the wrong number -----
3 9 23 99 479 2881 20159

Options

A. 9
B. 23
C. 99
D. 479

Answer

To solve the problem of finding the wrong number in the series: 3, 9, 23, 99, 479, 2881, 20159, we will analyze the pattern in the series step by step.

### Step-by-Step Solution:

1. **Identify the Series**:
The given series is:
\[ 3, 9, 23, 99, 479, 2881, 20159 \]

2. **Examine the Pattern**:
We will look for a pattern in how each number relates to the next.

3. **Calculate the Next Terms**:
- Start with the first term, \(3\):
\[ 3 \times 3 + 0 = 9 \]
- Now, take the second term, \(9\):
\[ 9 \times 3 - 4 = 23 \]
- Next, take the third term, \(23\):
\[ 23 \times 4 + 5 = 97 \quad (\text{This should be the next term, but we have } 99) \]
- Now, take the fourth term, \(99\):
\[ 99 \times 5 - 6 = 479 \]
- Then, take the fifth term, \(479\):
\[ 479 \times 6 + 7 = 2871 \quad (\text{This should be the next term, but we have } 2881) \]
- Finally, take the sixth term, \(2881\):
\[ 2881 \times 7 - 8 = 20159 \]

4. **Identify the Wrong Number**:
From the calculations, we see that:
- After \(23\), the expected term should be \(97\) instead of \(99\).
- Therefore, the wrong number in the series is \(99\).

5. **Conclusion**:
The correct number that should replace \(99\) is \(97\).

### Final Answer:
The wrong number in the series is **99**, and it should be replaced by **97**.

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