Find 3 mixtures and use a proedure to separate the ingredients

If you have salt, sand and iron filings, you separate the Iron filings by getting a magnet and pulling them out, and then you have a mixture of salt and sand, then by placing the mixture in water you will find that the salt dissolves but the sand remains. If this new mixture is then filtered, the salt in the salty water solution passes through the filter paper to form the filtrate and the sand remains as the residue.

The answer is 65.3312