Sure, I can help you create a test case generator for the problem statement "How old are you". Below is a Python function that generates random test cases based on the provided constraints:

```python
import random

def generate_test_case():
    # Number of queries N (1 ≤ N ≤ 15)
    N = random.randint(1, 15)
    
    queries = []
    
    for _ in range(N):
        # Type of query q (1 ≤ q ≤ 3)
        q = random.randint(1, 3)
        # Value of x (1 ≤ x ≤ 10)
        x = random.randint(1, 10)
        queries.append((q, x))
    
    # Format the test case as expected
    test_case = f"{N}\n"
    for query in queries:
        test_case += f"{query[0]} {query[1]}\n"
    
    return test_case.strip()

# Example usage
if __name__ == "__main__":
    print(generate_test_case())
```

This function generates a random number of queries (`N`) between 1 and 15. Each query consists of a type (`q`), which is randomly chosen between 1 and 3, and a value (`x`), which is randomly chosen between 1 and 10. The function then formats these queries into the appropriate input format suitable for the problem.

You can call the `generate_test_case()` function to generate a random test case and print it out, similar to what is shown in the example usage section.