1. **State the problem:** We need to find the missing numbers in sequences 8, 9, and 10. 2. **Sequence 8:** 120, 100, 80, __, 40. - This is a decreasing arithmetic sequence. - The difference between terms is $100 - 120 = -20$. - So, each term decreases by 20. - To find the missing term: $$80 + (-20) = 60$$ 3. **Sequence 9:** 2, 4, 6, __, 10, 12. - This is an increasing arithmetic sequence. - The difference between terms is $4 - 2 = 2$. - Each term increases by 2. - To find the missing term: $$6 + 2 = 8$$ 4. **Sequence 10:** 3, 6, 5, 10, 7, 14, __, 18. - This sequence alternates between two patterns: - Odd positions: 3, 5, 7, __ - Even positions: 6, 10, 14, 18 - Odd positions increase by 2: $3, 5, 7, 9$ - Even positions increase by 4: $6, 10, 14, 18$ - Missing term at position 7 (odd position) is 9. **Final answers:** - Sequence 8 missing number: 60 - Sequence 9 missing number: 8 - Sequence 10 missing number: 9