12 numbers
If you want 4-digit numbers, there are 24 of them.
With a total of 90,000 five digit numbers, we can conclude that there is 45,000 EVEN five digit numbers.
9
There are many answers. Here is one: 58 and 20
600 of them.600 of them.600 of them.600 of them.
With 123 digits you can make 123 one-digit numbers.
Not sure what a "didget" is. It is possible to make 18 5-digit numbers.
8
720 of them.
162
5040
6, as long as they are all different
12,13,14 21,23,24 31,32,34 43,42,41 12 two-digit numbers
There are no three didgit numbers but there are 63 three digit numbers.
3358
24 if you don't repeat any numbers.24
10999