Question

Michael is choosing a 2 letter password from the letters A, B, C, D, E, AND F. The password cannot have the same letter repeated in it. How many such passwords are possible?

Answer 1

6 possibilities for the first letter, 5 possibilities for the second letter:
combinations = 6·5 = 30

Answer 2

Answer: 30

Explanation:

Since, Total number of letter = 6 ( A, B, C, D, E, F)

And, according to the question we have to choose a 2 digit number.

But, there is no repetition of letter is not allowed.

So, the total possible password = P(5,2) =
`6_P_2` =
`(6!)/((6-2)!)`=
`(6!)/(4!)=(6* 5* 4!)/(4!) = 30`

Thus, Required possible password = 30.