While rolling two dice what is the probability of rolling a

While rolling two dice, what is the probability of rolling a sum of 7 or more?

Solution

While rolling two dice, what is the probability of rolling a sum of 7 or more?

Sample space

First Die

Second Die

1

2

3

4

5

6

1

2

3

4

5

6

7

2

3

4

5

6

7

8

3

4

5

6

7

8

9

4

5

6

7

8

9

10

5

6

7

8

9

10

11

6

7

8

9

10

11

12

The sample space is the set of all possible outcomes, 36 outcomes

Possible events( sum 7 or more) =21

The required P=21/36 =0.5833

First Die	Second Die
1	2	3	4	5	6
1	2	3	4	5	6	7
2	3	4	5	6	7	8
3	4	5	6	7	8	9
4	5	6	7	8	9	10
5	6	7	8	9	10	11
6	7	8	9	10	11	12