Whats the smallest number ("the magic number") that can satisfy these conditions?
- its positive
- it is not divisible by any number below 20 (excluding 1)
- the average of the digits is an even number between 3 and 9
Here is the problem as I see it.
When I read "the average of the digits is an even number between 3 and 9" my brain interpreted "even" as "whole number"
I assume this is because I know the average of a set of numbers is not usually a whole number.
In fact, had the orginal statement used "whole" rather than "even" the solution whould be 37 - the conclusion I jumped to.
Although the wording as it stands is _not_ ambiguous, is can be wrongly interpreted.
A better wording may be
- the average of the digits is an even whole number between 3 and 9
For a really easy problem this one has sparked quite the discussion.
Posted by Jer
on 2004-03-19 12:28:38