Question

Please type another way looking at it You have a bag with 20 marbles and you got to pick out the bag 3 times to try and pick the one blue marble. You will recored every color of marble u get everytime you draw. Since you draw 3 times, the total number of chances is 3 x 20= 60(Probability). So that leaves our chances of getting a blue marble 1/60 chances. So 1/60 gives you 0.0166666667=17% chances of you picking the blue marble out of they bag.Please type

Answer 1

Given, a bag with 20 marbles which contains a blue marble.

Now, 3 chances are given. So, blue marble may be picked in either of the 3 chances.

Probability to pick blue marble in first time = 1/20

Probability to pick blue marble in second time= 19/20 * 1/20 = 19/400 [Since marble is picked second time, no blue marble was picked in first chance which has a probability 1/20]

Probability to pick blue marble in third time = 19/20 * 19/20 *1/20 = 361/8000

Thus, total chances of getting a blue marble = 1/20 + 19/400 + 361/8000 = 1141/8000 = 0.142625

Thus 14.26% chances of picking the blue marble