50 to the 5th power.156,250 combination.
I can't
Possible 5 digit combinations using 5 digits only 1 time is 5! or 5*4*3*2*1 or 120. Using 5 digits where numbers can be used 5 times is 55 or 3125.
Combinations of 2: 20*19/(1*2) = 190 Combinations of 3: 20*19*18/(1*2*3) = 1140 Combinations of 4: 20*19*18*17/(1*2*3*4) = 4845 So 6175 in all.
There are 24 combinations using each digit once per combination: 1234 1243 1324 1342 1423 1432 2134 2143 2314 2341 2413 2431 3124 3142 3214 3241 3412 3421 4123 4132 4213 4231 4312 and 4321.
There are 1140 five digit combinations between numbers 1 and 20.
There are 1140 5 digit combinations from 1 to 20. 20 combination 3 computes that.
I am assuming you mean 3-number combinations rather than 3 digit combinations. Otherwise you have to treat 21 as a 2-digit number and equate it to 1-and-2. There are 21C3 combinations = 21*20*19/(3*2*1) = 7980 combinations.
There are 5,461,512 such combinations.
There are 840 4-digit combinations without repeating any digit in the combinations.
Just 1.
The answer will depend on how many digits there are in each of the 30 numbers. If the 30 numbers are all 6-digit numbers then the answer is NONE! If the 30 numbers are the first 30 counting numbers then there are 126 combinations of five 1-digit numbers, 1764 combinations of three 1-digit numbers and one 2-digit number, and 1710 combinations of one 1-digit number and two 2-digit numbers. That makes a total of 3600 5-digit combinations.
7
100
How many four digit combinations can be made from the number nine? Example, 1+1+2+5=9.
44
There are 9C2 = 9*8/(2*1) = 36 2-digit combinations.