Question

A jar contains 12 marbles. Four are red, 3 are white, and 5 are blue. A marble is randomly selected, its color recorded, and then the marble is NOT returned to the jar. A second marble is selected. What is the probability that a red and blue marble are selected?

Answer 1

1/11

Explanation:

Step one:

given

sample size

12 marbles.

sample space

4 red,

3 are white, and

5 are blue.

Step two:

when a marble is selected without replacement the sample size reduces.

the first selection is 4/12

The second selection is 3/11

The probability of the two events is

4/12*3/11

= 12/132

=1/11