Thought Leadership

Are you good enough?

By Colin Walls

Even though the UK is very much a secular country, we seem to go all out to celebrate Easter. Maybe it is because Passover is at a similar time; maybe it is because we actually like to mark the fact that Spring has sprung; or perhaps we just like chocolate. In any case, I am busy tidying up ready for a 4-day weekend, so only a quick post today.

I would like to set you a challenge …

Apparently, if you apply for a job with a certain well-known software company, who are headquartered in Washington State, you are subjected to a series of tests, some of which are to see just how smart you are. I looked at one of these – and failed. Maybe you would like to give it a go:

You know what a manhole cover looks like? Well, your answer may vary, depending on which country you are in. But, in the US anyway, all [or, at least, almost all] manhole covers are round. The question is: why are they that shape [and not square or rectangular or whatever]?

No, the answer is not “Because the holes are round”, even though that is true. The real answer is below.

My first thought was that a round shape tends to be strong and easy to make. It is also very symmetrical, so less prone to distortion as temperature varies. This is all correct, but it is not the primary reason. Which is:

There is no way that a round manhole cover can fall down the hole. This would not be the case if they were square or rectangular.

Would you pass the test? Seems that I need to try to hang on to the job that I have now …


0 thoughts about “Are you good enough?

Leave a Reply

This article first appeared on the Siemens Digital Industries Software blog at