what is the probability?

Question

An experiment consists of rolling a number cube. What is the probability of rolling two 4's in a row?

Answer 1

Since a "cube" is a regular solid with 6 faces, I assume you mean a die (plural is dice!).

The probability on the 1st throw is 1/6 and on the 2nd throw 1/6; therefore

the probability of 2 consecutive 4's is 1/36.

Another way to think of this is that the sample space is a 6 x 6 matrix each square of which has probability 1/36.

Answer 2

Hi Karla,

For this problem, you will want to start by finding the probability of rolling a single 4. Because there is only one 4 on the cube and 6 total sides, the probability is

1/6

Now, to find the probability of rolling two 4's in a row, multiply the two probabilities to get

1/6 * 1/6 = 1/36.

There is a 1 in 36 chance of rolling two 4's in a row.