Any 3 out of 4 = 4. Each set can be arranged 6 ways so 24 different numbers.
There is only one three digit number for a gross, and that is 144.
All the repeated ones are the mode.
450
There are 450 of them.
648
27 three digit numbers from the digits 3, 5, 7 including repetitions.
48 of them if digits may not be repeated. 100 if they can.
Using the digits of 1345678, there are 210 three digit numbers in which no digit is repeated.
757
It is possible to create a 3-digit number, without repeated digits so the probability is 1.
81 As there are no limits stated then you can have a number comprising a repeated single digit (such as 2222), two pairs of numbers (e.g. 2244) or three different numbers (such as 2462). The first digit can be one of any of the 3 numbers. The second digit can be one of any of the three numbers, as can the third digit and also the fourth. Then you can have 3 x 3 x 3 x 3 = 81 different 4-digit numbers using the three given numbers.
3897
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
1
512
24+24+12+4=64.
There are only two smaller 3-digit numbers and both of them have repeated digits.