mscroggs.co.uk
mscroggs.co.uk

subscribe

Sunday Afternoon Maths X

 Posted on 2014-04-27 

Lights

Source: Maths Jam
You have been taken captive and are blindfolded. There is a table in front of you with four lights on it. Some are on, some are off: you don't know how many and which ones. You need to get either all the lights on or all the lights off to be released. To do this, you can ask your captor to toggle the light switches of some of the lights. You captor will then rotate the table (so you don't know where the lights you toggled now are). Find a sequence of moves which will always lead to your release.

Show answer & extension

Princess problem

Source: Maths Jam
A princess lives in a row of 17 rooms. Each day she moves to a room adjacent to the one she wakes up in (eg. If she sleeps in room 5 today, then she will sleep in room 4 or 6 tomorrow). If you are able to find the princess by only opening one door each night then you will become her prince. Can you find her in a finite number of moves?

Show answer & extension

Three digit numbers

Brigette wrote down a list of all 3-digit numbers. For each of the numbers on her list she found the product of the digits. She then added up all of these products. Which of the following is equal to her total?
A \(45\)
B \(45^2\)
C \(45^3\)
D \(2^{45}\)
E \(3^{45}\)

Show answer & extension

Tags: numbers
If you enjoyed these puzzles, check out Advent calendar 2024,
puzzles about pentagons, or a random puzzle.

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

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

Archive

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