What will come in place of question mark (?) in the given number series?
116 ? 111 131 91 171

Options

A. 111
B. 121
C. 119
D. 115

Answer

To solve the number series problem, we need to identify the pattern between the numbers given in the series: 116, ?, 111, 131, 91, 171.

### Step-by-Step Solution:

1. **Write down the series**:
The series is: 116, ?, 111, 131, 91, 171.

2. **Identify the differences between the numbers**:
Let's calculate the differences between the numbers we know:
- From 111 to 131: 131 - 111 = +20
- From 131 to 91: 91 - 131 = -40
- From 91 to 171: 171 - 91 = +80

3. **Observe the pattern in differences**:
The differences are: +20, -40, +80.
We can see that the differences are alternating between addition and subtraction, and the absolute values of the differences seem to be doubling each time.

4. **Determine the missing number**:
Since the pattern is alternating, we need to find the difference that comes before +20.
The difference before +20 should be -10 (half of +20).
Therefore, to find the missing number (?), we subtract 10 from 116:
- 116 - 10 = 106.

5. **Check the series with the found number**:
Now, we can check if this fits into the series:
- 116, 106, 111, 131, 91, 171.
- The difference from 116 to 106 is -10.
- The difference from 106 to 111 is +5.
- The difference from 111 to 131 is +20.
- The difference from 131 to 91 is -40.
- The difference from 91 to 171 is +80.

6. **Conclusion**:
The missing number in the series is 106.

### Final Answer:
The number that will come in place of the question mark (?) is **106**.