34
36
172
874
102
34
36
How many strings of three digits are there? 000 to 999, or a total of 1000. How many strings of three digits contain the same three digits? That's 000, 111, 222 ... 999! ten in total. The difference is your answer: 1000-10 = 990.
172
102 is the smallest three digit number with different digits.
874
one hundred and thirty three
137?
102
smallest 8 digit number with three different digits
Six three-digit numbers contain only the digits 5 and 6. This is assuming you mean both the digits of 5 and 6. If not than 8, as it would include 555 and 666. 556, 565, 566, 655, 656, 665
> 9999876 Actually, 9999876 has four different digits (6, 7, 8, 9). The largest 7-digit number with three different digits is 9999987.