A three digit number is any counting number between 100 and 999 (inclusive). It is made up of three digits, the first of which cannot be 0.
0.12 Or 102 if you do not want to include non integers.
The smallest 3 digit counting number less than 1000?? 100
3
875
I am assuming you are referring to a normal 3x3 sudoku grid, where you can only use the numbers 1-9 once in the grid, and by prime number you mean the 3digit number across and down the grid must be prime? For a number to be prime, it must end in 1, 3, 7 or 9. There are 5 places on the Sudoku grid for a number to finish and as you can only use a number once in sudoku you have one place left where the number can not be prime. This means the most you can have is 5 prime numbers.
the answer is 135
2087
0.12 Or 102 if you do not want to include non integers.
196, 198, 202, 204
The smallest 3 digit counting number less than 1000?? 100
it is int n=123; printf ("%d", (n/10)%10);
4*9 = 36 so 360 is one possible answer.
3
266, 267, 268
2 is prime, its only factors are one and itself.
875
12