If the digit 0 is allowed then the answer is 1/(10*9*8) = 1/720 = 0.0014 approx. If 0 is disallowed, then 1/(9*8*7) = 1/504 = 0.0020 approx.
Any of the digits you did not choose are the most likely candidates
120 combinations using each digit once per combination. There are 625 combinations if you can repeat the digits.
Yes, unless the 3 digit number is negative, or a decimal.
Largest 4 digit number = 9999 Smallest 3 digit number = 111 9999 - 111 = 9888 Largest 4 digit number = 9999 Smallest 3 digit number = 111 9999 - 111 = 9888
There are no 3 digit numbers between 0 and 9 because 0 and 9 are 1 digit numbers.
528
528
There are 15180 combinations.
You should try out all of the three-digit combination. There are 10x10x10 = 1,000 possible combination (assuming digits 0-10).
679
bolt cutters....
There are 1140 5 digit combinations from 1 to 20. 20 combination 3 computes that.
30.The first digit can be one of three digits {3, 6, 9} corresponding to the last digit being {1, 2, 3}, and for each of those three digits, the middle digit can be one of ten digits {0 - 9}, making 3 x 10 = 30 such numbers.It is assumed that a 3 digit number is a number in the range 100-999, excluding numbers starting with a leading zero, eg 090 is not considered a 3 digit number (though it would be a valid 3-digit number for a combination lock with 3 digits).
Start dialing. If it's a three digit lock, then you can try all the possibilities in a reasonably short time. If it's a four digit lock, then it will obviously take longer, but it's still something a diligent person can manage in an afternoon. (If you try a combination per second, which isn't that hard, you can exhaustively search out a four-digit combination in at most 3 hours.)
You can crack a 3-digit combination lock by sequentially trying every possible number. Writing down and keeping track of every number used will help avoid confusion and speed up results.
Assuming you mean in the numbers 1, 2, 3, ..., 998, 999, 1000 then the digit 0. (The digit 1 appears 301 times, the digits 2-9 all appear 300 times each, but the digit 0 only appears 192 times.)