There are 60480 numbers.
There are 900 of them.
27 if the digits can be repeated. 6 if not.
More than one
48 of them if digits may not be repeated. 100 if they can.
24 different numbers.
If repetition of digits isn't allowed, then no13-digit sequencescan be formed from only 5 digits.
Using the digits of 1345678, there are 210 three digit numbers in which no digit is repeated.
Possible solutions - using your rules are:- 11,13,17,31,33,37,71,73 &77
the largest five digit number that can be formed using the digits 7 and 9 is 97,000