Find the wrong term in the following number series questions.
700,710,675,690,660,670,640

Options

A. 710
B. 675
C. 660
D. 690

Answer

To find the wrong term in the series 700, 710, 675, 690, 660, 670, 640, we will analyze the pattern of the series step by step.

### Step 1: Write down the series
The given series is:
700, 710, 675, 690, 660, 670, 640

### Step 2: Identify the pattern
Let's look at the differences between consecutive terms to identify a pattern:
- From 700 to 710: **+10**
- From 710 to 675: **-35**
- From 675 to 690: **+15**
- From 690 to 660: **-30**
- From 660 to 670: **+10**
- From 670 to 640: **-30**

### Step 3: Analyze the differences
Now, let's summarize the operations:
1. **700 to 710**: +10
2. **710 to 675**: -35
3. **675 to 690**: +15
4. **690 to 660**: -30
5. **660 to 670**: +10
6. **670 to 640**: -30

### Step 4: Look for a consistent pattern
If we observe closely, there seems to be an alternating pattern of adding and subtracting:
- **Add 10**
- **Subtract 35**
- **Add 15**
- **Subtract 30**
- **Add 10**
- **Subtract 30**

### Step 5: Identify the inconsistency
The pattern does not seem to be consistent. The second term (710) is followed by a subtraction of 35, which is not consistent with the expected pattern. If we were to follow a consistent alternating pattern, we would expect:
- After 700 (+10) = 710
- Next should be (-30) = 680 (not 675)

### Step 6: Conclusion
Thus, the wrong term in the series is **675**. If we replace 675 with 680, the series would follow a consistent pattern.

### Summary of the Correct Series
The corrected series would be:
700, 710, 680, 690, 660, 670, 640