There seems to be some debate about what happens with modes: mathforum.org/.../61375.html whilst Wolfram Alpha ducks the issue here: mathworld.wolfram.com/Mode.html I've seen the set 1, 2, 3, 4, 5 described as having both 'no mode' and as being 'multimodal' with modes of 1, 2, 3, 4, 5. On the GCSE papers, an example such as 2, 2, 3, 4, 4 is as difficult as it gets with modes of 2 and 4. Most GCSE textbooks I've seen, if they cover the issue, go for no mode with the set 1, 2, 3, 4, 5. I'd always thought the same thing but after reading the Dr. Math post I was a little more doubtful. What do others think?