10,000
100000 - including numbers with leading 0s
hi wazup hi wazup
There are no three didgit numbers but there are 63 three digit numbers.
18
5,040
It would help to know which digit. 0 appears in 9 numbers and each of the others in 18 numbers.
9
100,000
9,999 different combos well 10,00 if you add 0 in with it
5 x 10 x 5 = 250 different numbers, assuming there is no limit to each digits' use.
There are 9 of them.