Question

Two dice are rolled. What is the probability that the sum of the numbers rolled is either 7 or 10. Express your answer as a fraction in lowest terms or a decimal rounded to the nearest millionth.

Answer 1

The probability that the sum of the numbers rolled is either 7 or 10 is';

`(1)/(4)`

Here, we want to check if the sum of the numbers rolled is either 7 or 10

To do this, we need the right sample space

The sample space is as follows;

As we can see, the total number of expected results is 36

Now, we need the count of sums which are 7 or 10

The count of sums which are 7 is 6

The count of sums which are 10 is 3

The term 'or' between the probabilities mean that we are to add these fractions

We have this as;

`(3)/(36)+(6)/(36)\text{ = }(9)/(36)\text{ = }(1)/(4)`