“A detective is what I am, my dear Sergeant Simple”, as Professor Knowall has so often said to me.
“And detection is what I am interested in, even though the facts and objects to which you call my attention may appear to be only trivial and unimportant pawns in the game of life”.
When the mystery of the washing machine, therefore, was brought to my notice it seemed reasonable to take the professor at his word and put the facts before him.
This machine, I’m afraid, was not the washing machine it had been. Errors, inefficiencies and failure to wash had somehow crept in. I did not feel, however, that I could reveal the terrible things that this machine had been doing and I therefore decided that a screen of anonymity was required.
And so neatly anonymous did I make it that the results looked like this:
1. D, E is followed by q, r;
2. B, C, E is followed by q, s, t;
3. A, C, D is followed by p, t.
I showed this proudly to the professor, but I am afraid that his reaction was disappointing.
“Can’t you ever get things right, Sergeant?”, he said.
It is a humble Simple who has to confess to his public that the professor was once more quite right. There was one mistake in the causes, i.e., in the capital letters, so that to get it right one either has to cross one out or add another one (say, F).
On the assumption that each of the faults are caused by single events and not by two or more in conjunction or separately, what can you say about Sergeant Simple’s mistake and about the causes of the various defects?