Separate them by colour
One possible way to separate wooden marbles from glass marbles is by using a magnetic field. Since wooden marbles are typically not magnetic, while glass marbles are also not magnetic, one can use a strong magnet to attract and separate the wooden marbles from the glass marbles. The magnet will attract the wooden marbles while the glass marbles will remain unaffected and can be easily sorted out.
Pour into a sieve or colander, the sand will pass through the open mesh, leaving the larger marbles trapped inside the sieve.
It depends on what is in the mixture. If it's cake batter with flour, sugar, salt, butter, etc. then yeh it's basically impossible. But if it's a mixture of marbles and sand then you can easily separate those.
Because you can separate seashells and marbles with your hands and you can't with copper sulfate
In a beaker put in some marbles and 20ml of water.Using a filter funnel and filter paper let the water soak through the filter paper.
using a screen
Use a magnet.
D+J = 328 M+D = 176 J = 5M D+5M = 328 D+M = 176 subtract 4M = 152 M = 38 D = 176-38 = 138
Visual - the clue is in the question! Or use a magnet, assuming the steel marbles are not of a non-magnetic grade of stainless-steel.
I don't
You have to pick them up