Nine digits, four positions becomes 94 or 6561.
6561
1
There are 6804 such numbers.
The answer will depend on how many digits you have at your disposal. Working with the 10 digits, and barring leading zeros, there are 8,877,690 numbers.
27: 077,177,277,377,477,577,677,877,977,717,727,737,747,757,767,777,787,797
18
17
16000
There are 9000 4-digit numbers. 8*9*9*9 = 5832 of them do not contain a 5 The remaining 3168 contain a 5.
1
-2
In base ten, there are 9000 four digit number, the numbers are from 1000 to 9999. If you allow leading zeros, then there are 10000 numbers. [0000 - 9999]
three zeros
None. The only way for it to be possible would be 3 zeros which is not considered a 3 digit numbers.
It would help to know which digit. 0 appears in 9 numbers and each of the others in 18 numbers.
-5
-5
A Thousand digit number will have 999 zeros