Point of view

With reference to the comments on the travelling man Brain Teaser from Mike West and David Winter (Letters, 14 January) I appreciated that all points on the circle give a solution, but as these are indistinguishable as far as the problem is concerned, and to keep the words simple, I treated them all as one point.

I only spotted when explaining the solution to the Problem Page editor that there is a different infinity of solutions corresponding to multiple circuits at decreasing radius.

Docemus dicendi, the Romans used to say, if I remember my classics. I hoped I might use it for a later Brain teaser, but now that’s been blown.

Infinity of infinities — what would George Cantor have made of it?

Roger Flavell