Question

What is the probability of rolling a sum of 3 on a standard pair of six-sided dice?

Answer 1

To solve this problem, let us recall that the formula for probability is:

Probability = total number of successful events / total events

 

Where in this case, an event is considered to be successful if the sum is 3 on the pair of six sided dice.

 

First, let us calculate for the total number of events. There are 6 numbers per dice, therefore the total number of combinations is:

total events = 6 * 6 = 36

 

Next, we calculate for the total number of combinations that result in a sum of 3. We can identify that there are only two cases that result in sum of 3. That is:

1st case: first dice rolls 1, second dice rolls 2

2nd case: first dice rolls 2, second dice rolls 1

 

Hence, total number of successful events = 2. Therefore the probability is:

Probability = 2 / 36 = 1 / 18 = 0.0556 = 5.56%