That depends entirely on the number of digits each number is permitted to have !
45
I assume you mean how many 4-digit numbers can be made from a set such as {A,A, B, C} where A, B and C are single digits. There are 12 such numbers.
162
about 13
That depends entirely on the number of digits each number is permitted to have !
45
All numbers are made with digits and there is no limit on how big they can be. So there is no greatest number.
I assume you mean how many 4-digit numbers can be made from a set such as {A,A, B, C} where A, B and C are single digits. There are 12 such numbers.
depends on your answer
Assuming you mean permutations of three digits, then the set of numbers that can be made with these digits is: 345 354 435 453 534 543 There are six possible permutations of three numbers.
6
There are 24 number made by permutations of the digits. There are lots more if the digits can be repeated, for example, 27335722. Even more can be made by using arithmetic and algebraic operations, for example 35^27 = approx 4.8960*10^41. You have not specified what the rules for "making" numbers are!
162
6: 146, 164, 416, 461, 614, and 641.
about 13
Assuming you are treating each number as a number and not as an individual unit, the numbers you can make from these digits are 899, 989 and 998.