SOLUTION: Julian is looking at 6-digit locks for his football locker. How many diffrent codes are possible if no digit can repeat?

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Question 970797: Julian is looking at 6-digit locks for his football locker. How many diffrent codes are possible if no digit can repeat?
Found 2 solutions by AnlytcPhil, Boreal:
Answer by AnlytcPhil(1806) About Me  (Show Source):
You can put this solution on YOUR website!
We can choose the 1st digit any of 9 ways (can't choose 0).
Then we can choose the 2nd digit any of the 9 remaining ways (can choose 0).
Then we can choose the 3rd digit any of the 8 remaining ways.
Then we can choose the 4th digit any of the 7 remaining ways.
Then we can choose the 5th digit any of the 6 remaining ways.
Then we can choose the 6th digit any of the 5 remainingways.

Answer: 9*9*8*7*6*5 = 136080 ways.

Edwin

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Have 10 choices for first digit, 9 choices for the second, 8 for the third, 7 for the fourth, 6 for the fifth, and 5 for the sixth. There are 151,200 choices.
This is basically a tree diagram that would show 10 possibilities at the top, with each possibility having 9, and each of those having 8....