We are told that the spinner randomly lands on one part and found that the parts are numbered from 1 to 6, so there are 6 parts in total.
Recall that when you calculate probability, you compare the number of favorable outcomes to the number of possible outcomes.
P(Event)= Favorable Outcomes/Possible Outcomes
We want to find the theoretical probability of landing on a part that is not numbered 3. Note that this is the complement of selecting a part that is numbered 3. The sum of the probability of an event and the probability of its complement is 1.
P(Event)+P(Not event)=1
Let's start by finding the probability of landing on a part number 3, which will be our event.
The number of favorable outcomes is 1, and the number of possible outcomes is the total number of parts, 6.
P(3)=& Number ofpartsnumbered 3/Number of parts
P(3)=& 1/6
The theoretical probability of landing on a part number three is 16. Let's now find the probability of its complement, which is selecting a part that is not numbered three.
