You can
put this solution on YOUR website!
Hi,
In how many different ways can a chairperson and assistant chairperson be
selected if there are seven scientists available?
Order of Selections Important. This is a Permutation.
Number of permutations of a set of n objects taken r at a time is given by:
nPr = (n!)/(n - r)!.
7P2 = 7!/5! = 42 ways