Let's analyze and find the next two terms for each sequence:
1. \(3, 6, 12, 24, ...\): The pattern is doubling each time. Next terms: 48, 96.
2. \(9, 15, 21, 27, ...\): The common difference is 6. Next terms: 33, 39.
3. \(1.5, 2.25, 3, 3.75, ...\): The pattern is multiplying by 1.5. Next terms: 4.5, 6.75.
4. \(9.9, 8.8, 7.7, 6.6, ...\): The common difference is -1.1. Next terms: 5.5, 4.4.
5. \(1.5, 4.5, 13.5, 40.5, ...\): The pattern is multiplying by 3. Next terms: 121.5, 364.5.
6. \(40, 20, 10, 5, ...\): The pattern is dividing by 2. Next terms: 2.5, 1.25.
7. \(7, 11, 15, 19, ...\): The common difference is 4. Next terms: 23, 27.
8. \(67, 60, 53, 46, ...\): The common difference is -7. Next terms: 39, 32.
9. \(12, 7, 2, -3, ...\): The common difference is -5. Next terms: -8, -13.
10. \(4, 8, 12, 16, ...\): The common difference is 4. It is an arithmetic sequence.
11. \(-11, 5, 0, 6, ...\): It is not an arithmetic sequence.
12. \(4, 8, 16, 32, ...\): The common ratio is 2. It is a geometric sequence.
13. \(12, 23, 34, 45, ...\): The common difference is 11. It is an arithmetic sequence.
14. \(2, 4, 7, 9, ...\): It is not an arithmetic sequence.
15. \(1, 3, 9, 27, ...\): The common ratio is 3. It is a geometric sequence.