There are 9 yellow buttons and 8 red buttons in a bag. One button is selected at random. What is the probability of NOT selecting a red button?
- 9 yellow buttons
- 8 red buttons
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 red is selecting any other color.
- There are 9 non-red buttons out of 17 total buttons.
- So the probability is 9/17 = 9/17.
- A complement probability can also be found by doing 1 minus the probability of the event.
The correct answer is 9/17. This matches the calculation or definition, so students should focus on the reasoning rather than only memorizing the final value.