8 17 35 71 143 ?

Options

A. 286
B. 287
C. 238
D. 242

Answer

To solve the given series: 8, 17, 35, 71, 143, ?, we will analyze the pattern in the numbers.

### Step-by-Step Solution:

1. **Identify the Pattern**:
- The first number is 8.
- The second number is 17.
- The third number is 35.
- The fourth number is 71.
- The fifth number is 143.

2. **Observe the Relationship**:
- Let's examine how each number relates to the next:
- From 8 to 17:
\[ 8 \times 2 + 1 = 16 + 1 = 17 \]
- From 17 to 35:
\[ 17 \times 2 + 1 = 34 + 1 = 35 \]
- From 35 to 71:
\[ 35 \times 2 + 1 = 70 + 1 = 71 \]
- From 71 to 143:
\[ 71 \times 2 + 1 = 142 + 1 = 143 \]

3. **Apply the Same Pattern**:
- Now, we will apply the same operation to find the next number after 143:
\[ 143 \times 2 + 1 = 286 + 1 = 287 \]

4. **Conclusion**:
- Therefore, the next number in the series is 287.

### Final Answer:
The value of the question mark is **287**.