Find the probability for the experiment of drawing two marbles (without replacement) from a bag containing four green, two yellow, and four red marbles.

Question

Both marbles drawn from the bag are red.

Answer 1

There are 10 marbles in all, 4 of which are red. The probability of drawing the 1st red marble is 4/10. Since the marble drawn is not replaced there are now 9 marbles in all and 3 red marbles. The probability of drawing another red marble is 3/9.

now one needs to multiply 4/10 by 3/9 and that is the probability of drawing 2 red marbles without replacement.