Answer:
There is a 3/20 chance that a red plastic marble will be taken out on random.
Explanation:
This is because there are 14 yellow marbles, and 6 red marbles. Along with this, half of the red marbles are made out of plastic. This leaves 3/6 of the red marbles made out of plastic. When combined with the yellow marbles, you'll add 14 to the denominator, since there are 14 yellow marbles. (Red + Yellow = Total Number Of Marbles) This leads to a total count of 3 marbles of the 20 total marbles, being red and made out of plastic.