mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

17 December

Put the digits 1 to 9 (using each digit exactly once) in the boxes so that the sums and product are correct. Today's number is the product of the numbers in the red boxes.
++= 16
+ + +
++= 8
+ + +
××= 288
=
11
=
14
=
20

Show answer

Tags: numbers, grids

16 December

Solve the crossnumber to find today's number. No number starts with 0.

Show answer

15 December

When talking to someone about this Advent calendar, you told them that the combination of XMAS and MATHS is GREAT. They were American, so asked you if the combination of XMAS and MATH is great; you said SURE. You asked them their name; they said SAM.
Each of the letters E, X, M, A, T, H, S, R, U, and G stands for a different digit 0 to 9. The following sums are correct:
Today's number is SAM. To help you get started, the letter T represents 4.

Show answer

14 December

The numbers 33, 404 and 311 contain duplicate digits. The numbers 120, 15 and 312 do not.
How many numbers between 10 and 999 (inclusive) contain no duplicate digits?

Show answer

13 December

There are 6 ways to split the sequence of the numbers 1 to 5 into three shorter sequences:
Today's number is the number of ways to split the sequence of the numbers 1 to 10 into five shorter sequences.

Show answer

12 December

The diagram to the left shows a large black square. Inside this square, two red squares have been drawn. (The sides of the red squares are parallel to the sides of the black square; each red square shares a vertex with the black square; and the two red squares share a vertex.) A blue quadrilateral has then been drawn with vertices at two corners of the black square and the centres of the red squares.
The area of the blue quadrilateral is 167. What is the area of the black square?

Show answer

11 December

Noel has a large pile of cards. Half of them are red, the other half are black. Noel splits the cards into two piles: pile A and pile B.
Two thirds of the cards in pile A are red. Noel then moves 108 red cards from pile A to pile B. After this move, two thirds of the cards in pile B are red.
How many cards did Noel start with?
Note: There was a mistake in the original version of today's puzzle. The number 21 has been replaced with 108.

Show answer

10 December

Today's number is the smallest multiple of 24 whose digits add up to 24.

Show answer

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2020

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018


List of all puzzles

Tags

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2021