Earlier quoted context omitted.
>The one test that we gave that most people copied was converting decimal to roman number. I've read some really stupid programming questions, but that has got to be one of the top 5 stupidest. Also, I think you mean to say "integer," as Romans didn't have the concept of "decimal." http://mathforum.org/library/drmath/view/52552.html
Why stupid? As a take-home exercise it doesn't sound too bad. Won't take forever to solve but still requires some understanding of algorithms. Not as easy as FizzBuzz but also nothing you can't solve after work.
2. The question uses the term "decimal," rather than "integer." Roman numerals don't account for decimal numbers, so it's not even an accurately answerable question as posed.
3. When you google Roman Numerals and decimal, the first link tells you this. I assume the writer didn't event attempt to google.
4. The question will filter out candidates who don't know how roman numerals work and / or googled it to research how roman numerals work. Not only are these good candidates filtered out, but now they are telling all their other good candidate friends about that company and their stupid questions.
5. The pool of good candidates that will respond to your opening just temporarily diminished by a few people (depending on friends in #4)
6. For all this, the business didn't even test something that is in any way relevant to what that business does, unless that business is a digital clock face maker for smart watches or something.
If any one of these happened, that's bad. Way more thought and consideration should have gone into this question.