# Basic Question about a set

##### New member
F={Female students currently enrolled in an engineering program at the university of XYZ and who were born after Jan. 1,2005}

I cannot decide whether the cardinality of set F is 1 or 2 or whether this is an empty set.

The cardinality will be 1 if we say the element in set F is the whole sentence from the word Female till 2005

The cardinality will be 2 if we say the first element in set F is the sentence from the word Female till Jan. 1 and the second element is 2005; this is because of the comma.

The cardinality will be 0 if we say that this set is an empty set. This is because any student male or female who is born on (or after) 2005 will be at most 12 years old. No student of this age can be in engineering of University of XYZ.

What do you think is the cardinality of F?

Note: XYZ represents my university; its not fictional.

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#### Harry_the_cat

##### Senior Member
F={Female students currently enrolled in an engineering program at the university of XYZ and who were born after Jan. 1,2005}

I cannot decide whether the cardinality of set F is 1 or 2 or whether this is an empty set.

The cardinality can be 1 if we say the element in set F is the whole sentence from Female...2009

The cardinality can be 2 if we say the first element in set F is the sentence from Female... Jan. 1 and the second element is 200; this is because of the comma.

The cardinality can be 0 if we say that this set is an empty set. This is because any student male or female who is born on (or after) 2005 will be at most 12 years old. No student of this age can be in any program of University of XYZ.

What do you think is the cardinality of F?

Note: XYZ represents my university; its not fictional.
Nice little question. I'd say the cardinality is 0 interpreting the comma as part of the date (since it is usual to express a date in this format with a comma).

#### stapel

##### Super Moderator
Staff member
F={Female students currently enrolled in an engineering program at the university of XYZ and who were born after Jan. 1,2005}

I cannot decide whether the cardinality of set F is 1 or 2 or whether this is an empty set.

The cardinality will be 1 if we say the element in set F is the whole sentence from the word Female till 2005

The cardinality will be 2 if we say the first element in set F is the sentence from the word Female till Jan. 1 and the second element is 2005; this is because of the comma.

The cardinality will be 0 if we say that this set is an empty set. This is because any student male or female who is born on (or after) 2005 will be at most 12 years old. No student of this age can be in engineering of University of XYZ.
How did you arrive at your values of "1" and "2"? Is there some "universe" in which this set "F" lives, which is determining these values? If so, kindly please provide this missing information. Thank you!