Online Meeting of the Recreational Mathematics Group

Hi

You are invited to the meeting of the Recreational Mathematics Group, on Wednesday 6th April, at 7 pm. This meeting will be online using Zoom.

We will talk about a clever new way of explaining the operation of slide rules, using a construction based on rubber bands, an analogue analogy, so to speak. I came across this in a recent YouTube video in the excellent Mathologer series at:
https://www.youtube.com/watch?v=ZIQQvxSXLhI

If we have time we might discuss the Hat-Check puzzle, now more usually known as the problem of Derangements: A cloakroom attendant completely loses track of which of n hats belong to which customers, and hands them back at random to their n customers as the latter leave. What is the probability that none of the customers receive their own hat?

Michael Sheeran