Question

There is a bag filled with 5 blue, 6 red and 2 green marbles.
A marble is taken at random from the bag, the colour is noted and then it is replaced.
Another marble is taken at random.
What is the probability of getting 2 blues?

Answer 1

Answer:

Since the selected marble is replaced, the probability of getting a 2nd R = 6/13 as well. Thus the probability of getting 2R after 2 marble draws = (6/13)^2 = 36/139 = . 2589928…~ 25.9%.

Answer 2

Step-by-step explanation:

The probability of drawing blue marble is 5/13

and again since you're going to put it back and re-pick,

the probability will be same, Only this time you're looking if you can get two consecutive times, So if you pick any of the other two color you're going to do it all over again until you pick blue and see if you can pick blue again,

So the probability will take you to

5/13 0f 5/13 = 25/169