To separate the mixture of sand and sugar, it is best to use the separation technique of filtration then evaporation.
Pour the water into the mixture. The sugar will dissolve with time in the water. Sand is made up of quartz and does not dissolve in water.
After the dissolution, filter the solution to separate the sand using a filter paper.
Dry the sand thereafter then proceed to evaporate the sugar with water solution. Evaporation will turn water into vapor and the sugar crystals will be left behind.