If the digits may not be repeated, there are 6x5x4x3x2x1 = 720 numbers,
If digits can be repeated, the answer is 6x6x6x6x6x6 = 46,656 numbers
If zero is ong the available digits but is excluded from the first place. 5x6x6x6x6x6=38,880 numbers
There are 729 unique possibilities. This is 3 to the power 6. For each of the positions in the 6 digit result, the selected digit will be one of the three possibilities.
180 of them.
500
There are 34 = 81 numbers.
pizza
27
There are 7,290 different 4-digit numbers that can be formed from the digits 1-9 without repetition.
There are 3024 of them.
180 of them.
There are 60480 numbers.
840
24
500
27 three digit numbers from the digits 3, 5, 7 including repetitions.
There are 5*4*3 = 60 such numbers.
1 set
There are 5! = 120 such numbers.
The number 1234567890 can create about 39 of 40 4 digit numbers.