Two digit numbers: The two digits can be 2 and 9: Two possibilities 29 and 92.
Three-digit numbers: The three digits can be 1, 2 and 9 => 3! Or 6 possibilities.
We cannot have three digits as (3, 3, 2) as the digits have to be distinct.
We cannot have numbers with 4 digits or more without repeating the digits.
So, there are totally 8 numbers.
