_ _ _ _ _
2. the first digit is odd and larger than the third digit
3. the fourth digit is three times the first
That narrows it down to these four:
1 _ 0 3 _, 3 _ 2 9 _, 3 _ 1 9 _, 3 _ 0 9 _
1. all digits are different
4. the final digit is the product of the second and third digit
That rules out the 3rd digit being 0 or 1 for in either case it
would make the final digit be the same as the 3rd digit, but they
are all different. So we have
3 _ 2 9 _
4. the final digit is the product of the second and third digit
The only digit not used that we can multiply by third digit 2 and
get a different final digit is 4, and we get 4x2 = 8 for the final
digit.
Answer: 3 4 2 9 8
Edwin