1. **Problem Statement:** Determine the number of complete revolutions a motorcycle wheel will make in travelling 2 km, given the wheel’s diameter is 85.1 cm. 2. **Formula and Explanation:** The distance travelled by the wheel in one revolution is the circumference of the wheel, given by the formula: $$\text{Circumference} = \pi \times \text{diameter}$$ To find the number of revolutions, divide the total distance travelled by the circumference: $$\text{Number of revolutions} = \frac{\text{Total distance}}{\text{Circumference}}$$ 3. **Convert units:** - Diameter = 85.1 cm = 0.851 m (since 100 cm = 1 m) - Total distance = 2 km = 2000 m 4. **Calculate circumference:** $$\text{Circumference} = \pi \times 0.851 = 3.1416 \times 0.851 = 2.672 \text{ m}$$ 5. **Calculate number of revolutions:** $$\text{Number of revolutions} = \frac{2000}{2.672} \approx 748.5$$ 6. **Interpretation:** The wheel makes approximately 748 complete revolutions (since only complete revolutions count). **Final answer:** $$\boxed{748 \text{ complete revolutions}}$$