Advent calendar 2018

13 December

There is a row of 1000 lockers numbered from 1 to 1000. Locker 1 is closed and locked and the rest are open.
A queue of people each do the following (until all the lockers are closed):
Today's number is the number of lockers that are locked at the end of the process.
Note: closed and locked are different states.

Show answer


Show me a random puzzle
 Most recent collections 

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

Sunday Afternoon Maths LXV

Cryptic crossnumber #1
Breaking Chocolate
Square and cube endings

List of all puzzles


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


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2019