This is a permutation problem.
The digits are: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.
The 1st digit has 9 possibilities (it cannot be zero).
Thus, there are 9(9P9) = 9(9!) = 9(362,880) = 3,265,920 such numbers, because:
The 2nddigit has 9 possibilities (because we are left with 9 digits).
The 3rd digit has 8 possibilities.
The 4th digit has 7 possibilities.
The 5thdigit has 6 possibilities.
The 6thdigit has 5 possibilities.
The 7thdigit has 4 possibilities.
The 8thdigit has 3 possibilities.
The 9thdigit has 2 possibilities.
The 10thdigit has 1 possibility.
so that, 9*9*8*7*6*5*4*3*2*1= 3,265,920.
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
64 if repetition is allowed.24 if repetition is not allowed.
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.
Six (6)
If repetition of digits isn't allowed, then no13-digit sequencescan be formed from only 5 digits.
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.
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
If the number can contain repeated digits, the answer is 800000. Without repetition, there are 483840.
64 if repetition is allowed.24 if repetition is not allowed.
There are 7,290 different 4-digit numbers that can be formed from the digits 1-9 without repetition.
-4
If repetition of digits is allowed, then 56 can.If repetition of digits is not allowed, then only 18 can.
-123456787
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
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.