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.
7
Number of 7 digit combinations out of the 10 one-digit numbers = 120.
There are 840 4-digit combinations without repeating any digit in the combinations.
There are 1140 five digit combinations between numbers 1 and 20.
64
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.
7
1234, 1235 and 1236.
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 .
How many four digit combinations can be made from the number nine? Example, 1+1+2+5=9.
Assuming the digits are not repeated, there are four combinations:123, 124, 134 and 234.
There can be only one combination with four digits. Changing their order gives permutations, NOT combinations.The following are possible combinations:1 digit: 1, 4, 6.2 digit: 11, 14, 16, 463 digit: 114, 116, 146.
There are 15180 combinations.
9
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?
Number of 7 digit combinations out of the 10 one-digit numbers = 120.