Andrea is conducting an experiment rolling a pair of number cubes, numbered from 1 through 6. She will roll the number cubes 36 times to test the prediction of

Question

The rest of the question: Andrea is conducting an experiment rolling a pair of number cubes, numbered from 1 through 6. She will roll the number cubes 36 times to test the prediction of a 1 out of 6 chance of rolling matching numbers; that is, both cubes show the same number. If her experiment holds true to the prediction, how many of the 36 times would matching numbers appear?

 

A: 1

B: 18

C: 12

D: 6

Answer 1

This is a binomial situation...Fixed number of trials = 36....Probability is the same for each trial = 1/6

 

Expected value = (#trials)*(probability of success) = 36(1/6) = ???

 

To see this better, you might want to make a chart that shows the possible outcomes.  It would look something like:

 

Die 1  |  Die 2   | Same?

____________________

    1      |    1       |    YES

    1      |     2      |    N

    1      |     3      |    N

    1      |     4      |    N

    1      |     5      |    N

    1      |    6       |    N

    2      |    1       |    N

    2      |    2       |    YES

    2      |   3        |    N

 

Keep going like this until you get to 6 on both dice.  You can see that there are 36 possibilities and 6 are matches.