Advent calendar 2019

20 December

The integers from 2 to 14 (including 2 and 14) are written on 13 cards (one number per card). You and a friend take it in turns to take one of the numbers.
When you have both taken five numbers, you notice that the product of the numbers you have collected is equal to the product of the numbers that your friend has collected. What is the product of the numbers on the three cards that neither of you has taken?

Show answer


Show me a random puzzle
 Most recent collections 

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

List of all puzzles


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


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2020