1. **Problem Statement:** Find the relationship among the numbers in the zigzag line for Q1: points 9, 6, 18, 15. 2. **Observing the pattern:** The zigzag line has points arranged as 9 (top-left), 6 (bottom-left), 18 (top-right), 15 (bottom-right). 3. **Hypothesis:** The numbers might relate by multiplication or division between top and bottom points or by addition/subtraction. 4. **Check ratios:** - $\frac{9}{6} = 1.5$ - $\frac{18}{15} = 1.2$ Ratios differ, so direct division is unlikely. 5. **Check sums:** - $9 + 6 = 15$ - $18 + 15 = 33$ Sums differ, so addition is unlikely. 6. **Check products:** - $9 \times 6 = 54$ - $18 \times 15 = 270$ Products differ, no direct pattern. 7. **Check cross multiplication:** - $9 \times 15 = 135$ - $6 \times 18 = 108$ Close but not equal. 8. **Try difference between top points and bottom points:** - Top points difference: $18 - 9 = 9$ - Bottom points difference: $15 - 6 = 9$ This shows the difference between top points equals the difference between bottom points. 9. **Conclusion:** The relationship is that the difference between the top points equals the difference between the bottom points. **Final answer:** $$18 - 9 = 15 - 6 = 9$$ This is the relationship among the numbers in Q1 zigzag line.