What will come in place of question mark (? ) in the following number series ?
`4" " 9 " " 20 " " 43 " " 90 " " ?`

Options

A. 185
B. 195
C. 190
D. 186

Answer

To solve the number series: `4, 9, 20, 43, 90, ?`, we will analyze the pattern in the series step by step.

### Step 1: Identify the pattern
We will look at how each number in the series is generated from the previous number.

1. From **4** to **9**:
- Calculation: \(4 \times 2 + 1 = 8 + 1 = 9\)

2. From **9** to **20**:
- Calculation: \(9 \times 2 + 2 = 18 + 2 = 20\)

3. From **20** to **43**:
- Calculation: \(20 \times 2 + 3 = 40 + 3 = 43\)

4. From **43** to **90**:
- Calculation: \(43 \times 2 + 4 = 86 + 4 = 90\)

### Step 2: Continue the pattern
Now, we will apply the same pattern to find the next number in the series.

5. From **90** to the next number:
- Calculation: \(90 \times 2 + 5 = 180 + 5 = 185\)

### Conclusion
Thus, the number that comes in place of the question mark (?) is **185**.

### Final Answer
The answer is **185**.

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