Lewis Carroll, who died 125 several years in the past on Saturday, was probably the world’s finest populariser of rational puzzles. His most well known e book, Alice in Wonderland, is a masterclass in how to change arcane mathematical logic into whimsy and humour. Today’s worries start out with a small identified discussion involving two of Carroll’s finest-beloved characters.

1. A useful chat

Cheshire Cat: Okay Alice, let us get in touch with a entire amount ‘handy’ if its digits add to a numerous of 5. Can you consider of a helpful variety?

Alice: Why I can assume of lots! 14, 55, 406, 77777…

CC: Incredibly fantastic! But your illustrations are all quite considerably apart. How close collectively do you think two handy quantities can be?

Alice: Well… 55 and 64 are both helpful, and they are pretty close. Will that do?

CC: I think you can do improved than that.

Alice: Permit me feel…

What’s the very best you can do?

2. A cardy convo

Four cards numbered 1, 10, 100 and 1000 lie facial area down on a desk. The playing cards are distributed in between a few reality-tellers and a person liar, with each individual individual acquiring just one card. Then the four of them speak one soon after a further:

“My variety is odd.”

“My amount has 3 digits.”

“My number is less than 100.”

“My range is much more than 100.”

What variety was on the liar’s card?

(Clarification: reality-tellers generally notify the truth of the matter and liars always lie.)

Both of today’s Carrollian conundrums have been created by Daniel Griller, a British puzzle setter. His most up-to-date guide, A Ring of Cats and Canine, is out now.

Remember to NO SPOILERS In its place focus on Lewis Carroll.

I’ll be back again at 5pm Uk with the solutions.

I established a puzzle below just about every two weeks on a Monday. I’m often on the glance-out for fantastic puzzles. If you would like to advise one particular, email me.

I give university talks about maths and puzzles (on line and in particular person). If your college is intrigued make sure you get in touch.


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