11, 5, 20, 12, 40, 26, 74, 54

Options

A. 5
B. 20
C. 40
D. 26

Explanation

To find the wrong number in the series: 11, 5, 20, 12, 40, 26, 74, 54, we will analyze the differences between the numbers in the series and look for a consistent pattern.

### Step 1: Identify the series
The series given is:
11, 5, 20, 12, 40, 26, 74, 54

### Step 2: Separate the series into two parts
We can separate the series into two alternating sequences:
- Sequence A: 11, 20, 40, 74
- Sequence B: 5, 12, 26, 54

### Step 3: Analyze Sequence A
Let's look at Sequence A:
- From 11 to 20: the difference is 20 - 11 = 9
- From 20 to 40: the difference is 40 - 20 = 20
- From 40 to 74: the difference is 74 - 40 = 34

So, the differences in Sequence A are: 9, 20, 34.

### Step 4: Analyze Sequence B
Now, let's analyze Sequence B:
- From 5 to 12: the difference is 12 - 5 = 7
- From 12 to 26: the difference is 26 - 12 = 14
- From 26 to 54: the difference is 54 - 26 = 28

So, the differences in Sequence B are: 7, 14, 28.

### Step 5: Look for patterns in the differences
In Sequence A, the differences are increasing but not in a consistent manner.
In Sequence B, the differences are:
- 7 (which is 7)
- 14 (which is 7 * 2)
- 28 (which is 14 * 2)

This shows a doubling pattern in Sequence B.

### Step 6: Check for consistency in Sequence A
To maintain a similar pattern in Sequence A, we can check the next expected difference after 34. If we follow the pattern, we can assume the next difference should be:
- 9, 20, 34, and the next difference should be around 54 (which is 20 + 34).

### Step 7: Identify the wrong number
If we assume that the next number in Sequence A should be:
- 74 + 54 = 128 (which is not present in the series).

Now, we need to check the number that disrupts the pattern. The number 40 seems to be out of place because if we replace it with a number that fits the pattern, we would have:
- 11, 20, 38, 74 (instead of 40).

### Conclusion
The number that disrupts the pattern is **40**. The correct number should be **38**.

### Final Answer
The wrong number in the series is **40**.

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