Question

Help plz!!
Which of the following events are disjoint?
A.Choose a student at random from a statistics class. Event A is that the student is a junior. Event B is that the student is a senior.
B.Choose a student at random from a statistics class. Event A is that the student is a psychology major. Event B is that the student is a statistics major.
C.Choose a student at random from a statistics class. Event A is that the student is at least 5'8" tall. Event B is that the student weighs at least 160 pounds.

Answer 1

Disjoint means that the events cannot happen at the same time. There is no overlap.

Answer 2

Yeah, I know the definition, but they don't tell me how many students are under which category, so it seems to me that all of these can happen, unless it's the same student being described by event A and B?

Answer 3

You don't need to know any details about the statistics class or the students. The question is merely, "Is it POSSIBLE for events A and B to happen at the same time?"

For example, if event A is rolling a 2 on a die and event B is rolling an even number, event A and B can happen at the same time if I roll a 2.
If event A is rolling an odd number and event B is rolling an even number, they cannot happen at the same time because there is no overlap. They are disjoint.

Answer 4

And yeah, that's what they're trying to get at. They are only choosing one student.

Answer 5

Ok, I'd choose either A or B.... and im over complicating everything in my head with what if's, but I'm going to say A is the correct answer, did I get the right conclusion?

Answer 6

Why do you say A?

Answer 7

Rather than B

Answer 8

Students are usually one grade level, unless you have a student that is a sophomore with enough credits to have the standing of an upperclassmen, which I doubt the person who asked the question was thinking about... and B well there are some students that have double majors

Answer 9

Exactly right =) If we pick out a single student, they COULD be a double major in Psych and Stat, which would mean event A and event B also. They could be 5'8'' and 160 lbs, which would be event A and B for option C.

However, I think it's reasonable to assume they can't be both a Junior and a Senior.

Answer 10

Alright, thanks :)

Answer 11

Me pleasure =)

Answer 12

My*

Answer 13

hermaphrodites?

Answer 14

Lol, shootin' holes in my example, eh?

Answer 15

sorry had to do it:)