Question

Lucy rolls 2 fair dice and adds the results from each.

Work out the probability of getting a total that is a multiple of 5.

Answer 1

P(multiple of 5) = 7/36

Explanation:

A dice typically has numbers from 1 to 6. Now, since 2 dices are rolled, the possible sums of both numbers would range from 1 + 1 to 6 + 6. This can be easily written as from 2 to 12.

So, the possible multiples of 5 within this 2 to 12 range are; 5 and 10

Thus, first of all,the possible numbers on the two dice that add up to 5 are; (1,4) ( 4,1) (2,3) (3,2)

So there are 4 possible outcomes that could add up to 5.

Secondly,the possible numbers on the two dice that add up to 10 are; (5,5) (4,6) (6,4)

So there are 3 possible outcomes that could add up to 10

Hence, we have (4 + 3) = 7 possible outcomes for a multiple of 5

Now, in a double dice like this, there are 36 possible outcomes in total.

Thus;

P(multiple of 5) = 7/36

Answer 2

The probability is 7/36

Explanation:

In this question, we are tasked with calculating the probability that when we roll two fair dice, the sum of two numbers on both dies equal to 5.

Before we go on answering the question, we need to know the number of elements in our sample space. What this means is that we need to know the number of results we can have. The total number of results we can have is 6 * 6 = 36

Now, the next thing to know is how many of our results would yield a multiple of 5 each. Now let’s look at the attachment for the tabular representation we have.

Now, looking at our table, we can see that we have 7 circled results where we have a possibility of a multiple of 5.

The probability is thus the number of these additions divided by the total number of outputs= 7/36