Question

you roll a pair of number cubes. what is the probability of getting even numbers on both cubes? CHOICES: A]1/2, B] 1, C] 1/4, D] 1/7

Answer 1

P ( Even pairs ) = 1 / 4. ( Option C )

Explanation:

- It is best to draw a table of outcomes and list all the possible outcomes when you roll a pair of numbered cubes. As follows:

1 2 3 4 5 6

1 ( 1 , 1 ) ( 1 , 2 ) ( 1 , 3 ) ( 1 , 4 ) ( 1 , 5 ) ( 1 , 6 )

2 ( 2 , 1 ) ( 2, 2 ) ( 2 , 3 ) ( 2 , 4 ) ( 2 , 5 ) ( 2 , 6 )

3 ( 3 , 1 ) ( 3 , 2 ) ( 3 , 3 ) ( 3 , 4 ) ( 3 , 5 ) ( 3 , 6 )

4 ( 4 , 1 ) ( 4 , 2 ) ( 4 , 3 ) ( 4 , 4 ) ( 4 , 5 ) ( 4 , 6 )

5 ( 5 , 1 ) ( 5 , 2 ) ( 5 , 3 ) ( 5 , 4 ) ( 5 , 5 ) ( 5 , 6 )

6 ( 6 , 1 ) ( 6 , 2 ) ( 6 , 3 ) ( 6 , 4 ) ( 6 , 5 ) ( 6 , 6 )

- Each cube has 6 faces, Hence, 6 numbers for each are expressed as row and column for first and second cube respectively.

- Now locate and highlight all the even pairs shown in bold.

- The total number of even pairs outcomes are = 9.

- The total possibilities are = 36.

- The probability of getting even pairs as favorable outcome can be expressed as:

P ( Even pairs ) = Favorable outcomes / Total outcomes

P ( Even pairs ) = 9 / 36

P ( Even pairs ) = 1 / 4.

- So the probability of getting an even pair when a pair of number cubes are rolled is 1/4

Answer 2

When you roll a pair of number cubes, the probability of getting even numbers on both cubes is 1/6. There is a typo in your question, as it is not 1/7 but supposed to be 1/6. So the answer is D.