When you have a choice of 7 digits, and cannot repeat any digit, then the first number can be chosen in 7 ways, the second can be chosen in 6 and the third can be chosen in 5.
7 x 6 x 5 = 210
There are 2000 such numbers.
# 230 # 203 # 320 # 302
With repetition, 94 = 6561. Without repetition, 9*8*7*6 = 3024.
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.
There are 60480 numbers.
5040 different 4 digit numbers can be formed with the digits 123456789. This is assuming that no digits are repeated with each combination.
64 if repetition is allowed.24 if repetition is not allowed.
If repetition of digits isn't allowed, then no13-digit sequencescan be formed from only 5 digits.
I take it that you want to make three digits numbers with 8,7,3, and 6 without repetition. The first digit cane be selected from among 4 digits, the second from 3 digits, the third digit from 2, hence the number of three digit numbers that can be formed without repetition is 4 x 3 x 2 = 24
Six (6)
It is 415968.
9*8*7 = 504 of them.
3*2*1 = 6 of them.
There are 2000 such numbers.
Possible solutions - using your rules are:- 11,13,17,31,33,37,71,73 &77
To form a two-digit number using the digits 0-9 without repetition, the first digit (the tens place) can be any digit from 1 to 9 (9 options), since a two-digit number cannot start with 0. The second digit (the units place) can then be any of the remaining 9 digits (including 0 but excluding the first digit). Therefore, the total number of two-digit numbers that can be formed is 9 (choices for the first digit) multiplied by 9 (choices for the second digit), resulting in 81 possible two-digit numbers.
24 three digit numbers if repetition of digits is not allowed. 4P3 = 24.If repetition of digits is allowed then we have:For 3 repetitions, 4 three digit numbers.For 2 repetitions, 36 three digit numbers.So we have a total of 64 three digit numbers if repetition of digits is allowed.