Question

How to separate a mixture of common salt, sand and sulphur powder

Answer 1

Dissolve the mixture in water and filter it ... Sand and Sulphur will be obtained as residue in the filter paper.
Evaporate the water to obtain NaCl.
Take the mixture of Sand and Sulphur and dissolve in Carbon Disulphide ($CS _{2}$) or Carbon Tetrachloride ($CCl _{4}$) . Filter it to obtain Sand as residue and evaporate the filtrate to obtain Sulphur.