There are 4 green tiles and 5 yellow tiles in a bag. One tile is selected at random. What is the probability of NOT selecting a yellow tile?
- 4 green tiles
- 5 yellow tiles
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 yellow is selecting any other color.
- There are 4 non-yellow tiles out of 9 total tiles.
- So the probability is 4/9 = 4/9.
- A complement probability can also be found by doing 1 minus the probability of the event.
The correct answer is 4/9. This matches the calculation or definition, so students should focus on the reasoning rather than only memorizing the final value.