Answer
A)There are 24 possible permutations.
B)No
Work Step by Step
A)Find $_{4}$P$_{4}$:
$_{4}$P$_{4}$=$\frac{4!}{(4-4)!}$ -simplify-
$_{4}$P$_{4}$=$\frac{4!}{0!}$ -write using factorial-
$_{4}$P$_{4}$=$\frac{4*3*2*1}{1}$ -simplify-
$_{4}$P$_{4}$=24
There are 24 possible permutations.
B)No, especially if the name is short as it is more prone to hackers since there are only a number of possible passwords using the name