Dear Student,
Answer to your question is given below:
The speed of sound more in solid than liquid because molecules in solids are closer to each other compared to liquid, so the sound vibration (wave) can transfer from one molecule to the next more easily. The molecules in solids are so close, that they can collide very quickly, i.e. it takes less time for a molecule of the solid to 'bump' into its neighbouring molecules. Solids are packed together tighter than liquids and gases, hence sound travels fastest in solids. The distances in liquids are shorter than in gases, but longer than in solids. Molecules in solids are closer to each other compared to liquid, so the sound vibration (wave) can transfer from one molecule to the next more easily. The same way, as liquid molecules are closer to each other compared to gas, sound travels better through liquid than through gas.
Regards,