For group A, 100 people are divided into groups of 5 people, so * * * has (100! )/[5! ( 100-5)! ] a combined form;

Group B is the same, * * * can be divided into (100! )/[5! ( 100-5)! ] a combined form;

So the matching scheme is {( 100! )/[5! ( 100-5)! ]} 2 kinds

PS: By the way, is this a high school question?