I suppose that the manual separation is the most simple method.
Chromatography
some marbles are tiger, full moon, angel, bumblebee, cateye, bat, black widow, neptune, red rooster, red dragon, blue jay, blue sky, beachball, peewee, ghost, tiger shark, and more
Blue board
The names are arbitrary.Interestingly in all languages colours are named in order. First the difference between black and white is noticed. After that red is named, followed closely by green. Blue and yellow are distinguished next followed by purple, orange and brown in various orders. In Russian light blue and dark blue are treated as separate colours. Similarly to the treatment of pink in English.
Copper ores, will be heavier than most of the background rocks, and will generally be brightly coloured green or blue. Gravity separation usually suffices to separate the ore. The metal is separated from the ore by heating in a reducing atmosphere to remove sulphides, etc. The final preparation of the metal is by electrolytic refining.
Cupric oxide (black, CuO) is not soluble, so it is easily fitered off from the cupric sulfate solution (blue, CuSO4).
Chromatography
10 Green marbles, 13 Blue marbles.
12 blue marbles
12 blue marbles
He will have 13 blue marbles and 10 green marbles.
at least 39 blue marbles
Number of marbles in total = 90 Fraction of marbles are blue = five-ninth Number of blue marbles = five-ninth of ninety = 50 So, the answer is 50 blue marbles.
9:10
24 red marbles
If there are 20 red marbles and 40 blue marbles, the ratio of red to blue is 1 over 2. The number of white marbles does not matter.
24
12