mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

Square and cube endings

Source: UKMT 2011 Senior Kangaroo
How many positive two-digit numbers are there whose square and cube both end in the same digit?

Show answer & extension

What's the star?

In the Christmas tree below, the rectangle, baubles, and the star at the top each contain a number. The square baubles contain square numbers; the triangle baubles contain triangle numbers; and the cube bauble contains a cube number.
The numbers in the rectangles (and the star) are equal to the sum of the numbers below them. For example, if the following numbers are filled in:
then you can deduce the following:
What is the number in the star at the top of this tree?
You can download a printable pdf of this puzzle here.

Show answer

Archive

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

Tags

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

Archive

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