2 7 28 146 877 6140

Options

A. 877
B. 146
C. 6140
D. 28

Explanation

To solve the problem of finding the wrong number in the series: 2, 7, 28, 146, 877, 6140, we will analyze the pattern in the series step by step.

### Step-by-Step Solution:

1. **Identify the Series:**
The given series is:
\[ 2, 7, 28, 146, 877, 6140 \]

2. **Look for a Pattern:**
We need to find a pattern that connects these numbers. Observing the first two numbers:
- From 2 to 7, we can see that:
\[ 2 \times 3 + 1 = 6 + 1 = 7 \]

3. **Continue the Pattern:**
Now, let's check the next number:
- From 7 to 28:
\[ 7 \times 4 = 28 \]
- This follows the pattern of multiplying by an increasing integer.

4. **Check the Next Transition:**
Now, from 28 to 146:
- We can check:
\[ 28 \times 5 + 1 = 140 + 1 = 141 \quad (\text{This does not equal 146}) \]
- Instead, let's check:
\[ 28 \times 5 + 1 = 145 + 1 = 146 \quad (\text{This is correct}) \]

5. **Continue Checking:**
Now, from 146 to 877:
- Check:
\[ 146 \times 6 + 1 = 876 + 1 = 877 \quad (\text{This is correct}) \]

6. **Final Transition:**
Now, from 877 to 6140:
- Check:
\[ 877 \times 7 + 1 = 6139 + 1 = 6140 \quad (\text{This is correct}) \]

7. **Identify the Wrong Number:**
Now, we can see that the transition from 7 to 28 is correct, but we need to check the transition from 7 to 28:
- The correct number should be:
\[ 7 \times 4 + 1 = 29 \]
- Therefore, the wrong number in the series is 28, and it should be replaced with 29.

### Conclusion:
The wrong number in the series is **28**, and it should be **29**.