Can you solve it? Lewis Carroll fanfiction

Lewis Carroll, who died 125 years ago on Saturday, was perhaps the world's greatest popularizer of logic puzzles. His most famous book, Alice in Wonderland, is a masterclass in how to turn arcane mathematical logic into fantasy and humor. Today's challenges begin with a little-known conversation between two of Carroll's most beloved characters.

1. A practical conversation

Cheshire Cat: Ok Alice, let's call a whole number "practical" if its digits add up to a multiple of 5. Can you think of a number convenient ?

Alice: Why can I think of so much! 14, 55, 406, 77777...

CC: Great! But your examples are all quite far apart. How close do you think two practical numbers can be?

Alice: Well...55 and 64 are both practical, and they're pretty close. Will that be enough?

CC: I think you can do better than that.

Alice: Leave it me think... .

What better can you do?

2. A cardy convo

Four cards numbered 1, 10, 100 and 1000 lie face down on a table. The cards are divided between three truth tellers and one liar, with each person receiving a card. Then the four of them speak one after the other:

"My number is odd."

" My number is 3 digits."

"My number is less than 100."

"My number is greater than 100."< /p>

What number was on the liar's card?

(Clarification: truth tellers always tell the truth and liars always lie.)

Today's two Carrollian riddles were written by British puzzler Daniel Griller . His latest book, A Ring of Cats and Dogs, is now available.

PLEASE NO SPOILERS Talk about Lewis Carroll instead.

I'll be back at 5 p.m. with the answers.

I post a puzzle here every two weeks on a Monday. I'm always on the lookout for great puzzles. If you would like to suggest one, email me.

I give school lectures on math and puzzles (online and in person) . If your school is interested, please contact us.