గింజ మునుగుతుంది, కాయ తేలుతుంది?

వివరణ

This riddle asks 'the seed sinks, but the pod floats?' with the answer being groundnut/peanut shell. It's apt because when peanuts are harvested and soaked in water, the heavy seeds sink while the buoyant shell floats—a clever observation of nature that was used historically to separate the kernel from its pod.