The number of permutations of [tex] m(0\leq m\leq n) [/tex] objects from [tex] n [/tex] objects is [tex] P(m,n)=\frac{n!}{(n-m)!} [/tex].
The number of ways of choosing 3 digits from 6 digits without replacement ( order is important) is [tex] P(6,3)=\frac{6!}{(6-3)!} =\frac{6!}{3!} =4*5*6=120[/tex]. This is the number of all possible permutations of choosing 3 from 6.
Correct choice is 120.
