Concept:An open-ended problem permits multiple correct answers or multiple solution methods. A closed-ended problem has a single fixed answer.
Explanation:Examine each option:
Option A: “Find the cube of 10.” The only answer is 1000. This is closed-ended.
Option B: “Write any 5 numbers whose cube is more than 64.” Many numbers satisfy this, e.g., 5, 6, 7, 8, 9. There is no single correct set. Open-ended.
Option C: A cuboid of dimensions 5 cm, 2 cm, 5 cm requires a specific number of cuboids to form a cube. Only one exact count works. Closed-ended.
Option D: “Find the cube-root of 512 using prime factorisation method.” The answer is uniquely 8. Closed-ended.
Thus, only option B allows free-form responses with more than one correct answer.
Answer:Option B: Write any 5 numbers whose cube is more than 64.