Answer:
There is a
probability that the correct password is found on the sixth try.
Step-by-step explanation:
We have n passwords, only 1 is correct.
So,
Since a password is put back with other, at each try, we have that:
The probability that a password is correct is 
The probability that a password is incorrect is
.
There are 6 tries.
We want the first five to be wrong. So each one of the first five tries has a probability of
. So, for the first five tries, the probability of getting the desired outcome is
.
We want to get it right at the sixth try. The probability of sixth try being correct is
.
So, the probability that the first five tries are wrong AND the sixth is correct is:

There is a
probability that the correct password is found on the sixth try.