mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

Subsum

1) In a set of three integers, will there always be two integers whose sum is even?
2) How many integers must there be in a set so that there will always be three integers in the set whose sum is a multiple of 3?
3) How many integers must there be in a set so that there will always be four integers in the set whose sum is even?
4) How many integers must there be in a set so that there will always be three integers in the set whose sum is even?

Show answer & extension

If you enjoyed this puzzle, check out Sunday Afternoon Maths LII,
puzzles about numbers, or a random puzzle.

Archive

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

Tags

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

Archive

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