Here we need to see which of the given options are classified as an event. The correct options are:
A, C, and D.
We define an event as an outcome in a given experiment. So let's analyze the options.
A) "drawing a red card from a deck of cards"
The experiment is drawing a card from a deck, and the outcome is that the card is red, thus, this is an event.
B) "a blue marble"
This is just a blue marble, there is no experiment here, thus, this is not an event.
C) "choosing a math student in a group of students"
Here the experiment is choosing a student from a group and the outcome is that the student is a math student, thus, this is an event.
D) "rolling a number greater than 2 on a 6-sided number cube"
Here the experiment is rolling a dice, and the outcome is that the number is greater than 2, then this is an event.
E) "7 chairs in a room"
Like in option B, here we don't have any experiment, thus, this is not an event.
Then the correct options are A, C, and D.
If you want to learn more, you can read:
https://brainly.com/question/13342849
