Find the wrong number in following number series.
`540," "550," "575," "585," "608," "620," "645`

Options

A. A)608
B. B)550
C. C)575
D. D)645

Answer

To find the wrong number in the given series: 540, 550, 575, 585, 608, 620, 645, we will analyze the differences between consecutive terms to identify any inconsistencies.

### Step-by-Step Solution:

1. **Identify the Series**:
The given series is: 540, 550, 575, 585, 608, 620, 645.

2. **Calculate the Differences**:
- Difference between 550 and 540:
\( 550 - 540 = 10 \)
- Difference between 575 and 550:
\( 575 - 550 = 25 \)
- Difference between 585 and 575:
\( 585 - 575 = 10 \)
- Difference between 608 and 585:
\( 608 - 585 = 23 \)
- Difference between 620 and 608:
\( 620 - 608 = 12 \)
- Difference between 645 and 620:
\( 645 - 620 = 25 \)

So, the differences are: 10, 25, 10, 23, 12, 25.

3. **Analyze the Pattern**:
- The differences suggest a pattern:
- First difference: 10
- Second difference: 25
- Third difference: 10
- Fourth difference: 25 (expected)
- Fifth difference: 10 (expected)
- Sixth difference: 25

The expected pattern seems to alternate between 10 and 25.

4. **Identify the Anomaly**:
- The difference between 585 and 608 is 23, which does not fit the expected pattern of 25.
- Therefore, the term 608 is incorrect.

5. **Determine the Correct Term**:
- If we follow the pattern, after 585, the next term should be:
\( 585 + 25 = 610 \)
- The next term after that would be:
\( 610 + 10 = 620 \)

6. **Conclusion**:
- The correct series should be: 540, 550, 575, 585, **610**, 620, 645.
- Hence, the wrong number in the series is **608**.

### Final Answer:
The wrong number in the series is **608**.