Direction: What should come in place of question mark in the following number series?
40 59 97 173 325 ?

Options

A. 629
B. 529
C. 539
D. 641

Answer

To solve the number series: 40, 59, 97, 173, 325, ?, we will analyze the pattern in the differences between the consecutive numbers.

### Step-by-Step Solution:

1. **Identify the differences between consecutive numbers**:
- 59 - 40 = 19
- 97 - 59 = 38
- 173 - 97 = 76
- 325 - 173 = 152

So, the differences are: 19, 38, 76, 152.

2. **Observe the pattern in the differences**:
- The first difference is 19.
- The second difference is 38, which is 19 multiplied by 2.
- The third difference is 76, which is 38 multiplied by 2.
- The fourth difference is 152, which is 76 multiplied by 2.

We can see that each difference is double the previous difference.

3. **Calculate the next difference**:
- The next difference should be 152 multiplied by 2.
- 152 * 2 = 304.

4. **Add the next difference to the last number in the series**:
- 325 + 304 = 629.

5. **Conclusion**:
- The next number in the series is 629.

### Final Answer:
The number that should come in place of the question mark is **629**.