10+23 = 33
You can select 9 numbers for the first digit, 8 numbers for the second digit, and 7numbers for the third digit; so 504 (e.g. 9*8*7) different three digit numbers can be written using the digits 1 through 9.
Using the digits of 1345678, there are 210 three digit numbers in which no digit is repeated.
24 different numbers.
6 possible 3 digit combonations
9,999,876 is the greatest seven-digit number using four different digits.
You can select 9 numbers for the first digit, 8 numbers for the second digit, and 7numbers for the third digit; so 504 (e.g. 9*8*7) different three digit numbers can be written using the digits 1 through 9.
You have seven different digits (symbols) to choose from, so you can form seven different one digit numbers and 7×7=72=49 different two digit numbers.
Using the digits of 1345678, there are 210 three digit numbers in which no digit is repeated.
2222
24 different numbers.
5040 different 4 digit numbers can be formed with the digits 123456789. This is assuming that no digits are repeated with each combination.
The number of six digit numbers that you can make from ten different digits ifrepetitions of same digit on the six digit number is allowed is 1 000 000 numbers(including number 000 000).If no repetitions of the the same digit are allowed then you have:10P6 = 10!/(10-6)! = 151 200 different six digit numbers(six digit permutations form 10 different digits).
If you want 4-digit numbers, there are 24 of them.
6 possible 3 digit combonations
9,999,876 is the greatest seven-digit number using four different digits.
18
6 2-digit numbers (13/15/35/53/51/31)