Using each one only once, 5*4*3*2*1 = 120 of them.
3! = 6.
only using the numbers once
None.
24 of them.
There are a few options for listing five prime numbers using the digits zero to nine only once:2, 3, 5, 7, 8649012, 5, 13, 647, 809
61
9
3
Using each one only once, 5*4*3*2*1 = 120 of them.
I'm not sure what you're asking. The smallest number that can't be between two primes is obviously 1. Once you start running into primes, every composite number is between at least two primes.
3! = 6.
5*4+3+2
only using the numbers once
21 and three left over
24 this is a factorial if you come across a question like this again count how many then multiply down from that number. 4x3x2x1 for four 5x4x3x2x1 for five and so on
(5+7)*(5-3)=12*2=24