Final answer:
The cardinality of set A = {ø, {ø}} is 2.
Step-by-step explanation:
The cardinality of a set is a measure of the "number of elements" or the "size" of the set. It represents the count of distinct elements in a set. For finite sets, the cardinality is simply the number of elements in the set. For example, if a set A has elements {1,2,3}, then the cardinality of A is 3.
The cardinality of a set is the number of elements in the set. In this case, we have the set A = {ø, {ø}}.
The set A contains two elements. The first element is the empty set, denoted by ø. The second element is another set, which contains the empty set, {ø}.
Therefore, the cardinality of set A is 2.