What should come in place of question mark in questions
10 11 15 24 40 ?

Options

A. 90
B. 87
C. 114
D. 65

Answer

To solve the given sequence: 10, 11, 15, 24, 40, ?, we need to identify the pattern in the series.

### Step-by-Step Solution:

1. **Identify the Sequence**:
The numbers in the sequence are: 10, 11, 15, 24, 40.

2. **Find the Differences**:
- The difference between the first two numbers (11 - 10) is **1**.
- The difference between the second and third numbers (15 - 11) is **4**.
- The difference between the third and fourth numbers (24 - 15) is **9**.
- The difference between the fourth and fifth numbers (40 - 24) is **16**.

So, the differences are: 1, 4, 9, 16.

3. **Recognize the Pattern in Differences**:
- The differences (1, 4, 9, 16) can be recognized as perfect squares:
- 1 = 1²
- 4 = 2²
- 9 = 3²
- 16 = 4²

4. **Predict the Next Difference**:
- Following the pattern, the next difference should be 5², which is **25**.

5. **Calculate the Next Number**:
- To find the next number in the sequence, we add the next difference (25) to the last number (40):
- 40 + 25 = **65**.

6. **Conclusion**:
- Therefore, the number that should come in place of the question mark is **65**.

### Final Answer:
The answer is **65**.