Final answer:
The capacity of the bucket is 22,176 cm³.
Step-by-step explanation:
To find the capacity of the bucket, we need to calculate the volume of the frustum of the cone. The formula to calculate the volume of a frustum of a cone is given by:
V = (1/3)πh(R1² + R2² + R1R2)
Substituting the given values, we can calculate the capacity of the bucket:
V = (1/3)π(42 cm)(12 cm² + 20 cm² + 12 cm * 20 cm)
V = (1/3)π(42 cm)(144 cm² + 400 cm² + 240 cm²)
V = (1/3)π(42 cm)(784 cm²)
V ≈ 22,176 cm³
Therefore, the correct answer is a) 22,176 cm³.