Set Theory

Question 1

What is a set?

Answer 1

A set is a collection of unordered distinct elements

Question 2

What is a nullset?

Answer 2

A set with no elements in it.

Question 3

What is the cardinality of a set?

Answer 3

Number of elements which are present inside the set.

Question 4

Proper subset

Answer 4

Every element of A is present in B.

B has at least one element which A does not have.

denoted: A c B

Question 5

subset (denoted by c with underline)

Answer 5

A is a subset of B iff every element of A is present in B.

Question 6

superset

Answer 6

If A is a subset of B, then B is a superset of A

Question 7

Proper superset

Answer 7

If A is a proper superset of B, then B is a proper superset of A.

Every element present in B is present in A, plus at least one additional element.

Question 8

Power set

Answer 8

If A is a set, then set of all subsets of A is the power set of A.

Question 9

Power set

Answer 9

If A is a set, then set of all subsets of A is the power set of A.

Question 10

What are the set operations?

Answer 10

Union
intersection of 2 sests
complement of set
set Differences of 2 sets