Find the wrong number in the following number series.
8,12,24,60,180,640,2520

Options

A. 60
B. 180
C. 2520
D. 640

Answer

To find the wrong number in the series 8, 12, 24, 60, 180, 640, 2520, we will analyze the pattern in the series step by step.

### Step-by-Step Solution:

1. **Identify the Series**:
The given series is: 8, 12, 24, 60, 180, 640, 2520.

2. **Look for a Pattern**:
We will try to find a multiplication pattern between the consecutive numbers.

3. **Check the Multiplication Factor**:
- From 8 to 12:
\[ \frac{12}{8} = 1.5 \quad \text{(or multiply by 1.5)} \]
- From 12 to 24:
\[ \frac{24}{12} = 2 \quad \text{(or multiply by 2)} \]
- From 24 to 60:
\[ \frac{60}{24} = 2.5 \quad \text{(or multiply by 2.5)} \]
- From 60 to 180:
\[ \frac{180}{60} = 3 \quad \text{(or multiply by 3)} \]
- From 180 to 640:
\[ \frac{640}{180} \approx 3.56 \quad \text{(or multiply by approximately 3.56)} \]
- From 640 to 2520:
\[ \frac{2520}{640} = 3.9375 \quad \text{(or multiply by approximately 3.94)} \]

4. **Identify the Pattern**:
The multiplication factors appear to be increasing by 0.5:
- 1.5, 2, 2.5, 3, ...
However, the jump from 60 to 180 follows the expected pattern, but the jump from 180 to 640 does not fit the expected multiplication factor of 3.5.

5. **Calculate the Expected Value**:
If we follow the pattern:
- The next multiplication factor after 3 should be 3.5:
\[ 180 \times 3.5 = 630 \]
- Therefore, the expected number in the series after 180 should be 630, not 640.

6. **Conclusion**:
The wrong number in the series is **640**. The correct number should be **630**.