Find the biggest integer N such that:
1. All its digits are distinct.
2. Each of these digits divides N.
Only a p&p solution requested.
Bonus: What would be the answer, if one of N"s digits were exempted from being its divider?
(In reply to Bonus only--not the actual puzzle.
Without a computer: as you saw, 0 is out and if you get rid of 5 then 4 must be out and you are left with 7 digits only.
After a while IF you see that one digit more must leave - 9 of course...?..OR replace the 4 ,5, by 1,3,5..???..and leave 9 in..
Now it is not so difficult to carry on with p&p...
Edited on October 13, 2014, 10:22 am