From a committee of 8 person, a chairman and a vice chairman are to be chosen in such a way that one person cannot hold more than one position.
Here, the number of ways of choosing a chairman is the permutation of 8 different objects taken 2 at a time.
Thus, required number of ways= 8P2=8!(8−2)!=8!6!=8×7×6!6!=8×7=56