mscroggs.co.uk
mscroggs.co.uk

subscribe

Sunday Afternoon Maths LVI

 Posted on 2016-10-23 

An arm and a leg

If 60% of people have lost an eye, 75% an ear, 80% an arm and 85% a leg, what is the least percentage of people that have lost all four?

Show answer

Blackboard sums II

The numbers 1 to 20 are written on a blackboard. Each turn, you may erase two adjacent numbers, \(a\) and \(b\) (\(a\) is to the left of \(b\)) and write the difference \(a-b\) in their place. You continue until only one number remains.
What is the largest number you can make?

Show answer & extension

Tags: numbers
If you enjoyed these puzzles, check out Advent calendar 2023,
puzzles about rectangles, or a random puzzle.

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2023

Advent calendar 2022

Advent calendar 2021

Advent calendar 2020


List of all puzzles

Tags

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2024