Are you allowed to use a digit more than once? I will assume not:
There are 8 choices for the first digit. One digit has been used, so there are only 7 choices for the 2nd digit. ... 6 for the 3rd, etc.
The total number of numbers is 8x7x6x5x4 = 56x30x4 = 56x120 = 6720.
If you are allowed to repeat digits, then the answer is 85 = 32,768.
With 123 digits you can make 123 one-digit numbers.
6 if all digits are different, 27 otherwise.
1,956 different numbers can be made from 6 digits. You can calculate this by using the permutation function in a summation function, like this: Σ6k=1 6Pk = 6P1+6P2+...+6P5+6P6 What this does is calculate how many 1 digit numbers you can make from 6 digits, then how many 2 digit numbers can be made from 6 digits and adds the amounts together, then calculates how many 3 digit numbers can be made and adds that on as well etc.
Ten different digits can be used to make 10C4 = 10*9*8*7/(4*3*2*1) = 210 four-digit numbers. Either numbers starting with 0 are permitted or the 10 digits do not contain a 0.
4! = 24 ■
With 123 digits you can make 123 one-digit numbers.
6 if all digits are different, 27 otherwise.
There are 5460 five digit numbers with a digit sum of 22.
1,956 different numbers can be made from 6 digits. You can calculate this by using the permutation function in a summation function, like this: Σ6k=1 6Pk = 6P1+6P2+...+6P5+6P6 What this does is calculate how many 1 digit numbers you can make from 6 digits, then how many 2 digit numbers can be made from 6 digits and adds the amounts together, then calculates how many 3 digit numbers can be made and adds that on as well etc.
u culd make 80
9
Ten different digits can be used to make 10C4 = 10*9*8*7/(4*3*2*1) = 210 four-digit numbers. Either numbers starting with 0 are permitted or the 10 digits do not contain a 0.
27 three digit numbers from the digits 3, 5, 7 including repetitions.
If you want 4-digit numbers, there are 24 of them.
4! = 24 ■
There are 7,290 different 4-digit numbers that can be formed from the digits 1-9 without repetition.
7 two-digit numbers.