What will be come in place of the question mark (?) in the given number series
1 2 6 21 88 ?

Options

A. 425
B. 475
C. 295
D. 445

Answer

To find the missing number in the series: 1, 2, 6, 21, 88, ?, we can look for a pattern in the way the numbers are generated.

### Step-by-step Solution:

1. **Identify the Pattern**:
- The first number is 1.
- The second number is obtained by multiplying the first number by 1 and then adding 1:
\[ 1 \times 1 + 1 = 2 \]

2. **Continue the Pattern**:
- The second number is 2. The third number is obtained by multiplying the second number by 2 and then adding 2:
\[ 2 \times 2 + 2 = 6 \]

3. **Next Step**:
- The third number is 6. The fourth number is obtained by multiplying the third number by 3 and then adding 3:
\[ 6 \times 3 + 3 = 21 \]

4. **Proceeding Further**:
- The fourth number is 21. The fifth number is obtained by multiplying the fourth number by 4 and then adding 4:
\[ 21 \times 4 + 4 = 88 \]

5. **Finding the Missing Number**:
- Now, we need to find the sixth number. We take the fifth number (88), multiply it by 5, and then add 5:
\[ 88 \times 5 + 5 = 440 + 5 = 445 \]

Thus, the missing number in the series is **445**.

### Final Answer:
The answer is **445**.