99999
10
15 of them.
5040 numbers can be made.
24 of them.
There are 60480 numbers.
There are 4^6 = 4096 such numbers.
99999
8.
125
10
13579
There are 900 of them.
15 of them.
5040 numbers can be made.
there are 22
6, if you don't repeat any numbers.