A Solution and A Couple of New Problems

A solution and two new problems by way of a quick post before setting off for Marxism 2018.

INTRODUCTION

I am writing this immediately before setting off for Marxism 2018, a four-day political festival taking place in London. I should be able to do some posting at the event and at my accommodation. In my recent “An A-Z of Me” I included a mathematical problem from brilliant.org, and I now post the solution to that problem and offer you a couple of others.

THE SOLUTION

The problem I posted earlier was this:

plus-plus

The answer is that there is not, because it turns out that the perimeter of a plus-plus is always a multiple of four, which 2018 is not.

TWO NEW PROBLEMS

These are also both from brilliant.org. One is easy but generated a bit of controversy, while the other is very hard to solve properly, but by applying logic it can be easily worked out what the correct answer is. First, the hard problem:

clock problem

The easier problem which generated some controversy is this one:

Guards