This is the seventeenth puzzle in Matt Parker's Matt Parker's Maths Puzzles puzzle series
As the owner of a pet hotel, you have ten kennels in a row that you can put either a cat, or a dog into each night. Cats, being as they are, are not happy when placed adjacent to other cats. Dogs do not mind who they are next to though.
How many different ways are there to put cats and dogs into the ten kennels,
This is the sixteenth puzzle in Matt Parker's Matt Parker's Maths Puzzles puzzle series
Pascal's triangle is a tower of integers. The first row contains a
single 1 and subsequent rows are obtained by taking the sum of the two integers
above a number. Here are the first 5 rows
This is the fifteenth puzzle in Matt Parker's Matt Parker's Maths Puzzles puzzle series
Find a permutation of the numbers 1 to 9 such that the sum of any two adjacent numbers is prime.
This puzzle is the fourteenth puzzle from the Matt Parker's Maths Puzzles series.
If you have four cards numbered 1 to 4, how many of the 24 permutations contain no subsequence of length three that is increasing or decreasing?
The following javascript code will evaluate to itself:
(function f () {return `(${f})()`})()That is, if x = (function f () {return `(${f})()`;})(), then x === eval(x) is true.
Code snippets like this are known as quines. I first learnt about quines in a video by the AI researcher and youtuber Lex Fridman.
This puzzle is the twelfth puzzle from Matt Parker's Matt Parker's Maths Puzzles series.
You are creating a marching band. Your marching band must march in rows, but each row must have an equal number of performers in it. You want your marching band to be able to march in exactly 64 different formations.
When I was younger i had a great friend, Little Johnny. He was a very good boy. He woke up every morning at six sharp and promptly had a shower, ate his breakfast, and brushed his teeth before either leaving for school, or starting a shift in his mother's bakery on the weekends.
On one particular day at school the teacher annouced that we were going to have no more than two weeks to write speeches, which we would then have to present in front of the rest of the class. Johnny was stumped. He had absolutely
This puzzle is the eleventh puzzle from the Matt Parker's Maths Puzzles series.
David and Anton's ages combined equals 65. David is currently three times as old as Anton was when David was half as old as Anton will be when Anton is three times as old as David was when David was three times as old as Anton.
How old is David?
| from random import random | |
| def countBits(num): | |
| result = 0 | |
| while num: | |
| result += 1 | |
| num &= num - 1 | |
| return result | |
| def likelihood(probability): |