You can make
5 combinations of 1 number,
10 combinations of 2 numbers,
10 combinations of 3 numbers,
5 combinations of 4 numbers, and
1 combinations of 5 number.
31 in all.
There are 45 combinations.
6
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.
To calculate the number of combinations with three numbers, you would use the formula for combinations, which is nCr = n! / r!(n-r)!. In this case, n is the total number of numbers you have to choose from, and r is the number of numbers you are choosing. So, if you have three numbers to choose from, there would be 3C3 = 3! / 3!(3-3)! = 6 / (6*0!) = 6 / 6 = 1 combination.
There are 8!/[6!(8-6)!] = 8*7/2 = 28 - too many to list.
Their is 25 combinations
Assuming that the six numbers are different, the answer is 15.
14 * * * * * Wrong! There are 15. 4 combinations of 1 number, 6 combinations of 2 number, 4 combinations of 3 numbers, and 1 combination of 4 numbers.
The rearrangement of 5 figure numbers will be 5x4x3x2x1 which is 120 combinations, when you don't repeat a number.
There are 8*7/(2*1) = 28 combinations.
There are 11C2 = 11*10/(2*1) = 55 combinations.
There are 21 combinations.
none
There are 32C3 = 32*31*30/(3*2*1) = 4960 combinations. I do not have the inclination to list them all.
10 * * * * * That is just plain wrong! It depends on how many numbers in each combination but there are 1 combination of 4 numbers out of 4, 4 combinations of 3 numbers out of 4, 6 combinations of 2 numbers out of 4, 4 combinations of 1 number out of 4. A grand total of 15 (= 24-1) combinations.
Two make combinations you would take 2x1=2 combinations only
There are 233 - 1 = 8,589,934,591 combinations, not including the null combination.