10^7 if the repetition of digits is allowed. 9*8*7*6*5*4*3 , if the repetition of digits is not allowed.
There are 600 such numbers.
If repetition of digits isn't allowed, then no13-digit sequencescan be formed from only 5 digits.
You are not using the digit zero (0), so there are nine possible digits. If repetition is allowed and order is important (like a 4 digit combination lock), then the answer is 94 = 6561. If repetition is not allowed and order is important, then you have 9! / (9-4)! = 9*8*7*6*5 = 3024.
9*8*7 = 504 of them.
-123456787
290
20 of them, if repetition is not allowed.
10^7 if the repetition of digits is allowed. 9*8*7*6*5*4*3 , if the repetition of digits is not allowed.
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.
There are 600 such numbers.
30 without repetition (6P2) 66 with repetition (12C2)
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
You are not using the digit zero (0), so there are nine possible digits. If repetition is allowed and order is important (like a 4 digit combination lock), then the answer is 94 = 6561. If repetition is not allowed and order is important, then you have 9! / (9-4)! = 9*8*7*6*5 = 3024.
It is 415968.
9*8*7 = 504 of them.