500
It is 120 if the digits cannot be repeated.
There are 34 = 81 numbers.
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 repetition of digits isn't allowed, then no13-digit sequencescan be formed from only 5 digits.
There are 7,290 different 4-digit numbers that can be formed from the digits 1-9 without repetition.
27 three digit numbers from the digits 3, 5, 7 including repetitions.
24
500
There are 60480 numbers.
840
There are 3024 of them.
There are 5*4*3 = 60 such numbers.
1 set
It is 120 if the digits cannot be repeated.
There are 5! = 120 such numbers.
There are 34 = 81 numbers.