- Sand is insoluble in water
- If something is insoluble in something , then they will remain separated
- Therefore, sand will remain as solid particles in water

- Salt is soluble in water
- If something is soluble in something , then that something can be dissolved in something forming a solution
- Hence, salt will dissolve in water

- Sand will remain as solid particles in water
- Salt will dissolve in water
- So, adding water to salt and sand will produce a mixture of liquid and solid particles

- Adding water to salt and sand will produce a mixture of liquid and solid particles
- A filter is used for separating liquid from solid particles
- Therefore, a filter can separate sand from salt water

So, a filter can separate sand from salt water
Which mixture can be easily separated by adding water and pouring it through a coffee filter?
- Sand is insoluble in water 
- A filter is used for separating liquid from solid particles 
- Salt is soluble in water 
- If something is soluble in something , then that something can be dissolved in something forming a solution 
- If something is insoluble in something , then they will remain separated