100000 - including numbers with leading 0s
5040 different 4 digit numbers can be formed with the digits 123456789. This is assuming that no digits are repeated with each combination.
10,000
36
Assuming they are non-zero and different, the answer is 6.
24 different numbers.
27 three digit numbers from the digits 3, 5, 7 including repetitions.
There are 3024 of them.
180 of them.
840
There are 60480 numbers.
24
500