mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

4 December

The geometric mean of a set of n numbers is computed by mulitplying all the numbers together, then taking the nth root.
The factors of 9 are 1, 3, and 9. The geometric mean of these factors is
$$\sqrt[3]{1\times3\times9}=\sqrt[3]{27}=3$$
What is the smallest number where the geometric mean of its factors is 13?

Show answer

22 December

22 is two times an odd number. Today's number is the mean of all the answers on days (including today) that are two times an odd number.
Clarification: You are taking the mean for answers on days that are two times an odd numbers; ie. the days are two times odd, not the answers.

21 December

Today's number is a multiple of three. The average (mean) of all the answers that are multiples of three is a multiple of 193.
Tags: averages, mean

16 December

Today's number is four thirds of the average (mean) of the answers for 13th, 14th, 15th and 16th December.

Show answer

Mean, median, mode, range

A Find five one-digit positive integers which have a mean of 4, mode of 6, median of 4 and a range of 5.
B Find five one-digit positive integers which have a mean of 3, mode of 1, median of 1 and a range of 8.
C Find five one-digit positive integers which have a mean of 3, mode of 2, median of 2 and a range of 5.

Show answer & extension

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2025

Advent calendar 2024

Advent calendar 2023

Advent calendar 2022


List of all puzzles

Tags

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2026