THE MISSING POUND

The other day, I heard a radio presenter go on about how he’s spent thirty years trying to work out this puzzle. I’m going to try to reproduce it as he presented it, because as with most mathematical conundrums, the sleight-of-hand is all in the presentation, and where that slick maneouvre takes your assumptions.

It took me a while. See what you make of it.

Three people go to a restaurant and have a lovely time. At the end of the meal, the waiter presents them with a bill for exactly £30. They pay, and the waiter deposits the money into the till (cash register). Then, suddenly, the waiter realises that he’s overcharged the three diners by £5. So, he’s halfway back to the table... when he realises he could make himself a little profit by slipping £2 into his pocket. So that’s what he does. He returns the remaining £3 to the guests and keeps £2 himself.

The guests have now paid £9 each. £9 x 3 = £27. The waiter has £2 in his pocket. £27 + £2 = £29.

Where is the missing pound?

I bet it doesn’t take you thirty years. What’s interesting to me is the effect that puzzles like this have on my brain. As earlier, when I felt inadequate at reading, this kind of puzzle bends and twists my head beyond what I feel it’s capable of. It’s a lot like being in a second-year physics lecture. It sort of makes sense, and you’ve got a gut feeling that there’s some logic to it, but essentially the lecturer is using sleight-of-hand on the whiteboard with squiggles and numbers, and it’s just over the horizon of your understanding.

It could also be like being in a room with much cleverer people. That’s happened to me before - I had to fall back to my natural charm and charisma instead of intellectually debating, as I thought that might work well in a roomful of high-functioning super-engineers. I quickly realised how different my sense of humour was.

You know the feeling though. Puzzles sometimes make you feel like you’ve stumbled into a fraternity that you just don’t qualify for - where the atmosphere itself makes you feel inferior, and all you want to do is go home.

I hope this puzzle didn’t make you feel like that. Chances are you worked it out faster than I did while I listened to the radio presenter waffle on. Either that or you untwisted your brain and told yourself that this hypothetical fandango in a fictional restaurant just doesn’t matter.

And you’d be right - it really doesn’t. But then, maybe I’m like the sneaky waiter, trying to bamboozle you while I slip away. All I’ll say is this - think about where each pound is and what you’ve paid to whom.

Actually, that’s pretty good advice generally, isn’t it? Oh, and if you do find yourself in a roomful of incomprehensible brainiacs, be your funny, brilliant self and don’t let anyone make you feel inferior, or as though you’re lacking something. After all, if you can be confident enough to be you, there really is no missing pound at all... right?