Oh, dude, let me break it down for you. So, if you have 4 options for the first digit, 5 for the second, 6 for the third, and 7 for the fourth, you just multiply those numbers together. So, 4 x 5 x 6 x 7 equals 840 possible combination codes. Easy peasy, right?
There are 210 4 digit combinations and 5040 different 4 digit codes.
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In other words, how many 4 digit combination locks are there using the digits 0-9 on each wheel. There are 10×10×10×10 = 10⁴ = 10,000 such combinations.
Well honey, there are 4 numbers in your combination, so it's as simple as 4 factorial, which is 4 x 3 x 2 x 1, giving you a total of 24 combinations using the numbers 1, 4, 6, and 9. That's all there is to it, no need to complicate things.
Any 4 from 10 in any order = 10 x 9 x 8 x 7 = 5040
There are 210 4 digit combinations and 5040 different 4 digit codes.
104 or 10000
4
there are 4
There is only 1 combination.
3024
There can be 103 = 1000 codes.
I would have to say 10,000 possible combinations. (0000, 0001, 0002 through 9998, 9999)
5
120 combinations using each digit once per combination. There are 625 combinations if you can repeat the digits.
The number of 4 digit codes, using different digits, is 10*9*8*7 = 5040. However, computer passwords can, usually, have repeated digits and, if that is allowed, you can have 104 = 10000 codes.
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