seven which are
146
164
416
461
614
641
There are 60480 numbers.
There are 900 of them.
27 if the digits can be repeated. 6 if not.
27
24 different numbers.
48 of them if digits may not be repeated. 100 if they can.
More than one
If repetition of digits isn't allowed, then no13-digit sequencescan be formed from only 5 digits.
6
Possible solutions - using your rules are:- 11,13,17,31,33,37,71,73 &77
Using the digits of 1345678, there are 210 three digit numbers in which no digit is repeated.
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