If repetition of digits isn't allowed, then no13-digit sequences
can be formed from only 5 digits.
Assuming 9 numbers chosen from 56, with no repetition allowed, there are 7575968400 possible combinations.
If repetition is allowed . . . . . 343 If repetition is not allowed . . . . . 210
64 if repetition is allowed.24 if repetition is not allowed.
There are 504 of them.
125 different 4 digits numbers. To be divisible by 4, the last two digits must be divisible by 4, which means they must be: 12, 24, 32, 44 or 52 - 5 possible choices. For each of these there are 5 choices for the first digit and 5 for the second, meaning: total = 5 x 5 x 5 = 125
There are 10 to the 10th power possibilities of ISBN numbers if d represents a digit from 0 to 9 and repetition of digits are allowed. That means there are 10,000,000,000 ISBN numbers possible.
290
if the repetition is allowed the there is 6*6*6 possible ways = 216
Assuming 9 numbers chosen from 56, with no repetition allowed, there are 7575968400 possible combinations.
If repetition is allowed . . . . . 343 If repetition is not allowed . . . . . 210
-4
64 if repetition is allowed.24 if repetition is not allowed.
There are 2000 such numbers.
When the repetition is allowed: 4*4*4 = 64 numbers. Without repetition: 4*3*2 = 24 numbers.
There are 2000 such numbers.
There are 504 of them.
If repetition of digits is allowed, then 56 can.If repetition of digits is not allowed, then only 18 can.