Question

fiona needs to choose a five-character passord with a combination of three letters and the even numbers 0,2,4,6,or 8 if she uses her initial F,J,and S, in order as the first three characters and she does not use the same digit more than once in her passord how many different possible way are there

Answer 1

For the five characters of the five-character password, the first three slots are already taken for the initial F, J, S, the password would become,
                                         FJS_ _
The last two slots could be any of the even digits. In the fourth slot, Fiona can have any of the 5 values. On the fifth slot, she can have only 4 choices as the other digit was already used. Multiplying 5 and 4, the answer would be 20.