Question 1208471: One of the educational sites on the Internet requires the creation of
User account protected with 8 characters password
Different Choose from letters: A, B, C, D, E, F
And numbers: 6 , 5 , 4 , 3 , 2 , 1, find the number of passwords that
They can be created in the following cases:
The password contains 4 numbers and 4 letters combined together
Answer by greenestamps(13200)   (Show Source):
You can put this solution on YOUR website!
"... 4 numbers and 4 letters combined together" implies that any of the 8 characters chosen could be in any of the 8 positions. So...
(1) Choose 4 of the 6 letters in C(6,4) = 15 ways
(2) Choose 4 of the 6 digits in C(6,4) = 15 ways
(3) Order the 8 characters in 8! = 40320 ways
Number of different passwords: 15*15*40320 = 9072000
ANSWER: 9072000
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