Including the leading zero, then the answer is 210.
Or, allowing for repeating numbers, 10000.
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.
There are 9C3 = 84 combinations.
9
There are 45 combinations.
There are a huge number of combinations of 5 numbers when using the numbers 0 through 10. There are 10 to the 5th power combinations of these numbers.
9
9000
To calculate the number of different 4-digit combinations that can be made using numbers 0 through 9, we use the concept of permutations. Since repetition is allowed, we use the formula for permutations with repetition, which is n^r, where n is the number of options for each digit (10 in this case) and r is the number of digits (4 in this case). Therefore, the number of different 4-digit combinations that can be made using numbers 0 through 9 is 10^4, which equals 10,000 combinations.
The number of combinations is 10C4 = 10*9*8*7/(4*3*2*1) = 210
24
10P4 = 5040
If the numbers can be repeated and the numbers are 0-9 then there are 1000 different combinations.