In each of these question a number series is given in which one number is wrong find out wrong number
800 678 579 498 434 385 349

Options

A. 434
B. 498
C. 385
D. 678

Answer

To find the wrong number in the series 800, 678, 579, 498, 434, 385, 349, we can follow these steps:

### Step 1: Identify the series and calculate the differences between consecutive numbers.
The given series is:
- 800
- 678
- 579
- 498
- 434
- 385
- 349

Now, let's calculate the differences between each pair of consecutive numbers:
- Difference between 800 and 678: \( 800 - 678 = 122 \)
- Difference between 678 and 579: \( 678 - 579 = 99 \)
- Difference between 579 and 498: \( 579 - 498 = 81 \)
- Difference between 498 and 434: \( 498 - 434 = 64 \)
- Difference between 434 and 385: \( 434 - 385 = 49 \)
- Difference between 385 and 349: \( 385 - 349 = 36 \)

### Step 2: List the differences.
The differences we calculated are:
- 122
- 99
- 81
- 64
- 49
- 36

### Step 3: Analyze the pattern in the differences.
Now, let's observe the differences:
- 122
- 99
- 81 (which is \( 9^2 \))
- 64 (which is \( 8^2 \))
- 49 (which is \( 7^2 \))
- 36 (which is \( 6^2 \))

From the differences, we can see that starting from 81, the differences follow the pattern of squares of consecutive integers (9, 8, 7, 6).

### Step 4: Identify the expected difference.
If we follow the pattern, the difference before 81 should be \( 10^2 = 100 \), not 99. Therefore, the number before 579 should be:
- \( 579 + 100 = 679 \)

### Step 5: Determine the wrong number.
Since we expected the number to be 679 but it is 678, we can conclude that the wrong number in the series is 678.

### Conclusion:
The wrong number in the series is **678**.

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