To determine the probability of rolling a 1 or a 3 on this die, let's first outline the probability of each individual outcome:
Probability of rolling a
1,P(1) : Since there are 2 faces showing the number 1 , the probability is
‌.
Probability of rolling a
3,P(3) : There is 1 face showing the number 3 , so the probability is
‌.
To find the probability of rolling a 1 or a 3 , we use the rule for the union of two mutually exclusive events:
P(1∪3)=P(1)+P(3) Substituting the known probabilities:
‌P(1∪3)=‌+‌‌P(1∪3)=‌Thus, the probability of rolling a 1 or a 3 is
‌.