Coloured pins

A bowling alley has a mixture of red and blue pins. Ten of these pins are randomly chosen and arranged in a triangle.
Will there always be three pins of the same colour which lie on the vertices of an equilateral triangle?

Show answer & extension

Tags: colouring
If you enjoyed this puzzle, check out Sunday Afternoon Maths XLIII,
puzzles about colouring, or a random puzzle.


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


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


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