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

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

Archive

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