In case of A having 4 elements {a,b,c,d} with A as Identity element.Number of groups possible is given to be 2. I want to know why this
* |
a |
b |
c |
d |
a |
a |
b |
c |
d |
b |
b |
a |
d |
c |
c |
c |
d |
b |
a |
d |
d |
c |
a |
b |
Is not a group in given case.
Also is there any formula that can give us number of groups possible when cardinality of set A is given?