IN the following questions a number series is given in which one number is wrong. Find out the wrong number. Do not consider alternate series?
8 56 336 1680 6720 20040

Options

A. 6720
B. 1680
C. 56
D. 20040

Answer

To solve the problem of identifying the wrong number in the series: 8, 56, 336, 1680, 6720, 20040, we will analyze the pattern in the series step by step.

### Step 1: Identify the pattern
We will check how each number relates to the next number in the series by looking for a multiplication pattern.

### Step 2: Check the first two numbers
- Start with 8.
- Multiply 8 by 7:
\( 8 \times 7 = 56 \)
This is correct.

### Step 3: Check the next pair of numbers
- Now take 56.
- Multiply 56 by 6:
\( 56 \times 6 = 336 \)
This is also correct.

### Step 4: Check the next pair
- Now take 336.
- Multiply 336 by 5:
\( 336 \times 5 = 1680 \)
This is correct as well.

### Step 5: Check the next pair
- Now take 1680.
- Multiply 1680 by 4:
\( 1680 \times 4 = 6720 \)
This is correct.

### Step 6: Check the next pair
- Now take 6720.
- Multiply 6720 by 3:
\( 6720 \times 3 = 20160 \)
This is where we notice a discrepancy.

### Step 7: Compare with the given number
- The series gives us 20040 instead of 20160.
Therefore, 20040 is the wrong number.

### Conclusion
The wrong number in the series is **20040**.

---