Determine whether the sets below are well-defined or not. For each well-defined set, state whether it is finite or infinite.
a) The set of women pregnant with twins at some time during this year.
b) The set of kangaroos in Australia.
c) The set of tall buildings.
d) The set of grains of sand on the earth.
e) The set of even integers.
f) The set of hairs on your head.
g) The collection of all subsets of the set of hairs on your head.
h) The set of people who shook hands with George Washington.

Question

Determine whether the sets below are well-defined or not.  For each well-defined set, state whether it is finite or infinite.
a) The set of women pregnant with twins at some time during this year.
b) The set of kangaroos in Australia.
c) The set of tall buildings.
d) The set of grains of sand on the earth.
e) The set of even integers.
f) The set of hairs on your head.
g) The collection of all subsets of the set of hairs on your head.
h) The set of people who shook hands with George Washington.

anonymous · Answer

a. finite
b. finite
c. finite
d. finite
e. infinite
f. finite
g. finite
h. finite

anonymous · Answer

It asked are they well-defined and I am not sure how to tell if they are well-defined.

anonymous · Answer

What's well defined mean?

anonymous · Answer

She has confused herself, I'm sure.

anonymous · Answer

I confused myself? The question does not ask you are they finite or infinite until you have answered are they well defined.  Well defined means for every object x, there must be an unequivocal answer to the question.

anonymous · Answer

The set of tall buildings.

anonymous · Answer

It's well defined, because tall means 100 feet.

anonymous · Answer

The set of tall building is not well defined because tall could be any height depending on the person describing tall.