Question

Which of the following does not represent the set of integers from 1 to 12?

{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}

{integers from 1 to 12}

{1, 2, 3, … 10, 11, 12}

{1, 2, 3, 4, …}

Answer 1

What do you think about the first two choices?

Answer 2

im thinking A

Answer 3

A is a set that has all the integers from 1 to 12.
Does A represent the set of integers from 1 to 12?

Answer 4

but why ?

Answer 5

check both the restrictions

Answer 6

FROM 1 TO 12

Answer 7

which doesnt satisfy the condition ?

Answer 8

Remember the problem is asking for the set that DOES NOT represent the integers from 1 to 12.

Answer 9

Choice A is {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}.
Does the set of choice A contain all the integers from 1 to 12?

Answer 10

Ohhhhh so it is B

Answer 11

No. How about we go through each set, one at a time, and we focus on that set.
I think by now you understand that choice A DOES represent the set of all integers from 1 to 12, so A is not the answer. Ok?

Answer 12

NO < ITS D!!!! ; D goes from 1 to infinity

Answer 13

Now let's look at choice B.

Answer 14

all others r same as A

Answer 15

@JOELMATHEWS1234 just go away

Answer 16

Choice B is the same as choice A.
Instead of listing all integers from 1 to 12, it describes that the set consists of all integers from 1 to 12, so choice B is not the answer either.

Answer 17

WHAT ?? @gurrilabill

Answer 18

Ok with A and B not being the answer?

Answer 19

im getting confused

Answer 20

@mathstudent55 , u teach , bro :D

Answer 21

I'm out

Answer 22

Now we can look at choice C.
The set starts with integers 1, 2, 3.
The three dots means to continue with similar numbers, that is, only integers.
Then it ends with 10, 11, 12.
That means choice C is a set that contains all integers from 1 to 12.
Once again, this is not the answer.

Answer 23

Now by the process of elimination, you see that the answer has to be D, but it's better to look at it and to understand why.

Answer 24

@mathstudent55 : Thanks for your patience and persistence under such trying circumstances.

Answer 25

Thank you so much @mathstudent55

Answer 26

Choice D starts also with 1, 2, 3, 4.
That means integers 1, 2, 3, and 4 are part of it.
Then we again see three dots.
The three dots mean continue with similar numbers.
That means continue with more integers such as 5, 6, 7, 8, and so on.
Since there is no number at the end to stop at, this set consists of all integers, starting at 1 and going on forever with larger integers than 1.
This is not a set of only the integers from 1 to 12, so this is the correct answer.

Answer 27

@mathmale You're welcome. The point here is to be patient and to not get distracted.

@gurrilabill You're welcome. I hope that by going through all the choices you understand what they mean and why only choice D is the correct answer.