The whole point of combinations is that the order of the number (or items) does not matter. Once you specify what the second number is, you are no longer looking at combinations.
If repeats are allowed than an infinite number of combinations is possible.
2 to the 7th power = 128 * * * * * No. That is the total number of combinations, consisting of any number of elements. The number of 2 number combinations is 7*6/2 = 21
4*3*2*1 = 24 different combinations.
You Can Create 999 Number combinations
6 of them.
How many four digit combinations can be made from the number nine? Example, 1+1+2+5=9.
We are not told anything about repeats so I will assume you can repeat a digit. For example, you can have 111111 The first digits has 50 choices so does the second and the third..etc so we have 50^6 combinations.
8C6 = 28
9!/5! or 3024
If every number can be used as many times as you like, there are 104 = 10000 different combinations. If each number can only be used once, there are 9!/(9 - 4)! = 5040 combinations.
Obviously, you must let me repeat numbers. If you didn't, then I couldn't makeany 4-number combinations out of only 3 numbers.The first number can be any one of 3. ( 9, 2, or 0). For each of those . . .The second number can be any one of 3. For each of those . . .The third number can be any one of 3. For each of those . . .The fourth number can be any one of 3.So the total number of possible combinations is (3 x 3 x 3 x 3) = 81 .
The number of combinations of six numbers that can be made from seven numbers will depend on if you can repeat numbers. In all there are over 2,000 different numbers that can be made.