mscroggs.co.uk
mscroggs.co.uk
Click here to win prizes by solving the mscroggs.co.uk puzzle Advent calendar.
Click here to win prizes by solving the mscroggs.co.uk puzzle Advent calendar.

subscribe

Sunday Afternoon Maths LII

 Posted on 2016-04-24 

Subsum

1) In a set of three integers, will there always be two integers whose sum is even?
2) How many integers must there be in a set so that there will always be three integers in the set whose sum is a multiple of 3?
3) How many integers must there be in a set so that there will always be four integers in the set whose sum is even?
4) How many integers must there be in a set so that there will always be three integers in the set whose sum is even?

Show answer & extension

More doubling cribbage

Source: Inspired by Math Puzzle of the Week blog
Brendan and Adam are playing lots more games of high stakes cribbage: whoever loses each game must double the other players money. For example, if Brendan has £3 and Adam has £4 then Brendan wins, they will have £6 and £1 respectively.
In each game, the player who has the least money wins.
Brendan and Adam notice that for some amounts of starting money, the games end with one player having all the money; but for other amounts, the games continue forever.
For which amounts of starting money will the games end with one player having all the money?

Show answer & extension

If you enjoyed these puzzles, check out Advent calendar 2019,
puzzles about shapes, or a random puzzle.

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

List of all puzzles

Tags

indices triangles factorials shapes cryptic clues pascal's triangle the only crossnumber division products 3d shapes tiling gerrymandering floors multiplication numbers 2d shapes integers quadratics perfect numbers scales coins complex numbers fractions colouring cryptic crossnumbers triangle numbers sport doubling factors lines averages proportion cards means graphs digits hexagons crossnumbers crossnumber dates sum to infinity median number functions taxicab geometry range palindromes geometry books probability clocks circles wordplay integration ave logic dice remainders surds routes square roots algebra digital clocks multiples polygons mean chocolate area star numbers irreducible numbers calculus probabilty people maths folding tube maps sequences crosswords shape grids elections planes perimeter unit fractions balancing percentages trigonometry cube numbers chalkdust crossnumber games sums squares partitions prime numbers dodecagons bases rugby dominos coordinates chess odd numbers speed advent time spheres rectangles arrows menace volume square numbers christmas symmetry parabolas angles money differentiation regular shapes addition ellipses

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2020