A password is a string of 8 characters taken from the alphabet (that is, the set of 26 characters {a, b, c, ..., x, y, z}), the set of 10 digits {0, 1, 3, 4, 5, 6, 7, 8, 9} and the set of 5 special characters {!, @, #, ∗, +}. How many unique passwords are there where no character can be repeated and there are exactly 2 digits? Keep in mind No character should be repeated including digits. Therefore, the question is asking you to calculate the unique passwords with no repeated characters and with exactly 2 digits. There are 10 choices for the first digit, 9 choices for the second digit. Same goes for the other characters. You should think to choose 2 locations for the digits and then think of the other 6 locations. No character can be repeated
A password is a string of 8 characters taken from the alphabet (that is, the set of 26 characters {a, b, c, ..., x, y, z}), the set of 10 digits {0, 1, 3, 4, 5, 6, 7, 8, 9} and the set of 5 special characters {!, @, #, ∗, +}.
How many unique passwords are there where no character can be repeated and there are exactly 2 digits? Keep in mind No character should be repeated including digits. Therefore, the question is asking you to calculate the unique passwords with no repeated characters and with exactly 2 digits. There are 10 choices for the first digit, 9 choices for the second digit. Same goes for the other characters. You should think to choose 2 locations for the digits and then think of the other 6 locations. No character can be repeated
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