There are three arts of chameleon: red, blue, yellow. One morning there are 20 blue, 30 yellow, 50 red. In the evening 100 red. Is it possible?If...

From the information given in the question there are
originally 50 red, 30 yellow and 20 blue creatures. Also we know that if two creatures
of different color meet, both change to the 3rd color and if two creatures of the same
color meet half of them change to the second color and half to the
third.

So let's
start:

Initially there were 50 red
creatures.

Now let 20 of the blue and 20 of the yellow
creatures meet, all 40 change to red.

So now we have 90 red
and 10 yellow.

Now let the ten meet each other, 5 turn to
red and 5 turn to blue.

Now let 4 of the yellow meet each
other, 2 change to red and two to blue.

So we have 1
yellow, 2 blue and the rest red.

Now when the two blue
meet, we have 1 red and 1 yellow.

Finally the two yellow
meet, 1 turns red and the other blue.

Therefore finally
there are 99 red and 1 which can either be blue or yellow depending on how you go about
it.

It is not possible to get all red
finally.