If upper-case and lower-case letters are considered as different litters, how many six-letter computer passwords are possibile with no repeated letters?
I thought it was 52 pick 6, but its not, why wouldn't it be 52x51x50x49x48x47?
Explanation would be greatly appreciated.
It's not choose, its pick.
Pick refers to permutations while Choose refers to combinations. Pick is way different than choose.
I have several examples in my textbook and its gives me the formula
nPr = n! / (n-r)!
Heres an example:
In a card game, each player is dealt a face down "reserve" of 13 cards that can be turned up and used one by one during the game. How many different sequences of reserve cards could a player have?
Solution
Here, you are taking 13 cards from a deck of 52.
52Pick13 = 52! / (52-13)!
=52!/39!
=52x51x50x...x41x40
=3.9543x10^21
Straight from the textbook