mscroggs.co.uk
mscroggs.co.uk

subscribe

Advent calendar 2020

24 December

There are six ways to put two tokens in a 3 by 3 grid so that the diagonal from the top left to the bottom right is a line of symmetry:
Today's number is the number of ways of placing two tokens in a 29 by 29 grid so that the diagonal from the top left to the bottom right is a line of symmetry.

Show answer

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2020

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018


List of all puzzles

Tags

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2021