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 2024

Advent calendar 2023

Advent calendar 2022

Advent calendar 2021


List of all puzzles

Tags

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2025