Directions: Insert the missing number: 5, 10, 13, 26, 29, 58, 61, (.....)

### Concept & Logic The sequence follows an alternating pattern of mathematical operations: multiplying by 2, then adding 3. ### Step-by-Step Solution Let's analyze the transition between terms: - From 5 to 10: $5 \times 2 = 10$ - From 10 to 13: $10 + 3 = 13$ - From 13 to 26: $13 \times 2 = 26$ - From 26 to 29: $26 + 3 = 29$ - From 29 to 58: $29 \times 2 = 58$ - From 58 to 61: $58 + 3 = 61$ The pattern is clearly $\times 2, + 3, \times 2, + 3$. The last operation was $+ 3$. Therefore, the next operation must be $\times 2$. $61 \times 2 = 122$. ### Exam Strategy & Shortcut Look for groupings. When you see numbers that jump significantly and then increase slightly (e.g., 10 to 13, 26 to 29), suspect a multiplying and adding combination. ### Common Pitfall Trying to find a single, continuous difference pattern for the entire sequence, which will quickly become convoluted and unsolvable. ### Final Answer Therefore, the correct answer is **122**.