mscroggs.co.uk
mscroggs.co.uk

subscribe

Advent calendar 2022

11 December

There are five 3-digit numbers whose digits are all either 1 or 2 and who do not contain two 2s in a row: 111, 112, 121, 211, and 212.
How many 14-digit numbers are there whose digits are all either 1 or 2 and who do not contain two 2s in a row?

Show answer

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2024

Advent calendar 2023

Advent calendar 2022

Advent calendar 2021


List of all puzzles

Tags

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2025