When I have been involved with running exams (I wasn’t, really, this year), special care seems to be made to spread these out so that where possible students don’t get exams bunched together. Still, I’ve heard students complain “we only have one day off between the Monday and Wednesday exams, that isn’t enough time to revise for the second topic”. I have a lot of sympathy for this; assessing a module (or proportion thereof) by how you perform in a one-, two- or three-hour window is quite a problematic arrangement, and if you haven’t had sufficient time to get up to speed on the topic, even more so. But I have had in mind that, essentially, “when I were a lad, we had it much worse”. Clearing out some boxes to move house, I found exam timetables from five of the six semesters I spent as an undergraduate, so now I can confirm or refute my feeling on this, in the latest of my series of posts that are surely only of interest to me.

# You're reading: Columns

### Binary/Nail Varnish Puzzle – solution

Previously, we posted about Katie’s Binary Nail varnish tutorial video, and how you can use glitter (`1`

) and no glitter (`0`

) to encode binary messages in your nail varnish. We also posted an accompanying puzzle, stated as:

**Suppose I want to paint my nails on one hand differently every day for a month – so I need to use all 31 combinations involving glitter. Assuming that a nail painted with plain varnish can have glitter added, but a nail with glitter needs to be nail-varnish-removed before it can become a plain nail again, what order do I apply the different combinations so that you minimise the amount of nail varnish remover I’ll need to use?**

Here’s our take on the solution.

### Puzzlebomb – June 2016

Puzzlebomb is a monthly puzzle compendium. Issue 54 of Puzzlebomb, for June 2016, can be found here:

Puzzlebomb – Issue 54 – June 2016

The solutions to Issue 54 can be found here:

Puzzlebomb – Issue 54 – June 2016 – Solutions (printer-friendly version)

Previous issues of Puzzlebomb, and their solutions, can be found at Puzzlebomb.co.uk.

### Carnival of Mathematics 135

The next issue of the Carnival of Mathematics, rounding up blog posts from the month of May, and compiled by Gaurish, is now online at Gaurish4Math.

The Carnival rounds up maths blog posts from all over the internet, including some from our own Aperiodical. See our Carnival of Mathematics page for more information.

### Just how big is a big proof?

With news that a recent proof of the Boolean Pythagorean Triples Theorem is the ‘largest proof ever’, we collect and run-down some of the biggest, baddest, proofiest chunks of monster maths.

### Armadillo Vault held together only by friction

More information at Wired.

*via math-fun.*

### “How can you do coursework for maths?” What I marked this year

A while ago I was helping out at an open day. The material presented gave some information about the range of assessment types we use. A potential applicant asked me “how can you do coursework for maths?”. She felt that (what she understood as) maths could only be assessed by examination. (This is presumably because her experience of the English school system has not exposed her to anything but exams for maths.)

I thought it might be interesting (to me, at least) to list the types of assessment I’ve been involved in marking in the 2015/16 academic year.