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}

{1, 2, 3, …, 10, 11, 12}

{1, 2, 3, 4, …}

{integers from 1 to 12}

Answer 1

{1, 2, 3, 4, ...} does not represent a set of integers from 1 to 12 because "...}" means continue on forever following the preceding pattern

Answer 2

How do I find this out?, I don't understand integers.

Answer 3

whereas the first solution specifies the entire set, and the second solution also specifies the set of integers from 1 to 12 but leaves the middle section as a repeating pattern from 3 to 10

Answer 4

Integers are whole numbers ( http://en.wikipedia.org/wiki/Integer )

Answer 5

do you understand how a set is specified?

Answer 6

NO So confusing
>.>

Answer 7

first think of everything as a single object
{anything in here no matter what it is and the two brackets on either side}

that whole thing is the list. A set is a collection of well defined and distinct objects( http://en.wikipedia.org/wiki/Set_(mathematics) ).

To use an analogy say you go shopping, think of the { } as a shopping cart
now you head around the store and put things in your cart
{ bananas, cereal, milk, cookies, eggs }
now I can ask a question about your cart (set)
Does your cart contain bananas?
and yes it does.

Now change that to numbers
{ 1, 2, 3, 4}
Does your set contain the integer 1?
Yes it does.

Hopefully that helps some, but with that analogy the '...' notation doesn't really work
{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
is the same thing as
{1, 2, ..., 10}