There are 12 yellow tokens and 7 green tokens in a bag. One token is selected at random. What is the probability of NOT selecting a green token?
- 12 yellow tokens
- 7 green tokens
Choose the best answer.
Note
For a “not” event, count the outcomes outside the named event. This is the complement of the event.
- The complement of selecting green is selecting any other color.
- There are 12 non-green tokens out of 19 total tokens.
- So the probability is 12/19 = 12/19.
- A complement probability can also be found by doing 1 minus the probability of the event.
The correct answer is 12/19. This matches the calculation or definition, so students should focus on the reasoning rather than only memorizing the final value.