Method 1: four digit number start after 999 and end at 9999so 4 digit no. = 9999-999 = 9000method 2: - - - - there are four places in 4 digit no. In first place only 1-9 can come , for rest 0-10so total no. = 9*10*10*10=9000* * * * *Wrong!Those are the number of PERMUTATIONS, not combinations. In a combination, the order of digits does not matter. So 1234 is the same as 1342 or 4213 etc.
This is the UN Identification Number.
It is 0.000009 approx.
Assuming that the first digit of the 4 digit number cannot be 0, then there are 9 possible digits for the first of the four. Also assuming that each digit does not need to be unique, then the next three digits of the four can have 10 possible for each. That results in 9x10x10x10 = 9000 possible 4 digit numbers. If, however, you can not use the same number twice in completing the 4 digit number, and the first digit cannot be 0, then the result is 9x9x8x7 = 4536 possible 4 digit numbers. If the 4 digit number can start with 0, then there are 10,000 possible 4 digit numbers. If the 4 digit number can start with 0, and you cannot use any number twice, then the result is 10x9x8x7 = 5040 possilbe 4 digit numbers.
This question needs clarificatioh. There are 4 one digit number combinations, 16 two digit combinations, ... 4 raised to the n power for n digit combinations.
Assuming the digits are not repeated, there are four combinations:123, 124, 134 and 234.
The number of four-digit combinations is 10,000 .Stick a '3' before each of them, and you have all the possible 5-digit combinations that start with 3.There are 10,000 of them. They run from 30,000 to 39,999 .
3690 is one example.
How many place combinations in a four digit number and all have to go in different spot example: 1234, 4321, 2134 etc. numbers can't change and have to stay four numbers?The answer would be 36 different combinations. This is simply the counting principle and it's easy for anyone to learn.
every number from 0000 to 9999
1234, 1235 and 1236.
It is already a four-digit number.
There are 12C4 4 NUMBER combinations. And that equals 12*11*10*9/(4/3/2/1) = 495 combinations. However, some of these, although 4 number combinations consist of 7 digits eg 1, 10, 11, and 12. Are you really sure you want 4-DIGIT combinations?
Lowest four-digit number: 1000 Highest four-digit number: 9999