There are 5! = 120 such numbers.
There are 4 possible numbers if the digits are not repeated; 18 if they are. Those are 3-digit numbers, assuming that zero would not be a leading digit. If zero is allowed for a leading digit, then you can have 6 for the non repeated, and 27 if repetition.
738 numbers
There are 5760 such numbers.
1 set
757
823543
720 (10*9*8)
625 if numbers can have leading 0s, 500 otherwise.
9x9x8x7x6x5x4x3 =1632960
There are 5! = 120 such numbers.
81
9x9x8x7x6x5 = 81x56x30 = 136080
There are 4 possible numbers if the digits are not repeated; 18 if they are. Those are 3-digit numbers, assuming that zero would not be a leading digit. If zero is allowed for a leading digit, then you can have 6 for the non repeated, and 27 if repetition.
162
27 three digit numbers from the digits 3, 5, 7 including repetitions.
738 numbers