Answer:
there are twelve total combinations
Step-by-step explanation:
just by looking at the problem though,
ABCD
AB
AC
AD
BA
BC
BD
CA
CB
CD
DA
DB
DC
normally, because some of them are repeated, we need to get rid of some
AB
AC
AD
BC
BD
DC
since this is about passwords though, we need to keep all of the same twelve combinations because the order of the letters are important
