In each of the following questions a number series is given in which only one number wrong . Find out the wrong number
3 9 23 99 479 2881 20159

Options

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

Answer

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

### Step 1: Identify the Pattern
Let's look at the differences between consecutive numbers in the series:

- 9 - 3 = 6
- 23 - 9 = 14
- 99 - 23 = 76
- 479 - 99 = 380
- 2881 - 479 = 2402
- 20159 - 2881 = 17278

So, the differences are: 6, 14, 76, 380, 2402, 17278.

### Step 2: Analyze the Differences
Now, let's look at the differences of the differences:

- 14 - 6 = 8
- 76 - 14 = 62
- 380 - 76 = 304
- 2402 - 380 = 2022
- 17278 - 2402 = 14876

The second level differences are: 8, 62, 304, 2022, 14876.

### Step 3: Look for a Consistent Pattern
Now, let's analyze the second level differences:

- 62 - 8 = 54
- 304 - 62 = 242
- 2022 - 304 = 1718
- 14876 - 2022 = 12854

The third level differences are: 54, 242, 1718, 12854.

### Step 4: Identify the Anomaly
The differences do not seem to follow a consistent pattern, but we can see that the jump from 99 to 479 is quite large compared to the previous jumps.

### Step 5: Check the Number 99
Let's check if 99 is the wrong number by calculating what the number should be if we follow a pattern:

If we assume that the series is growing exponentially or by a certain factor, we can see that:

- The first few numbers seem to be increasing rapidly, and the jump from 23 to 99 is much larger than the previous jumps.

### Step 6: Replace 99
If we replace 99 with a smaller number, say 47, we can check if the series continues to make sense:

- New series: 3, 9, 23, 47, 479, 2881, 20159

Calculating the differences again:

- 9 - 3 = 6
- 23 - 9 = 14
- 47 - 23 = 24
- 479 - 47 = 432
- 2881 - 479 = 2402
- 20159 - 2881 = 17278

This seems to create a more consistent pattern.

### Conclusion
Thus, the wrong number in the series is **99**.