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Advent calendar 2018
11 December
All 2018 advent puzzles
~
More information
This puzzle is inspired by
a puzzle Woody showed me at MathsJam
.
Today's number is the number \(n\) such that $$\frac{216!\times215!\times214!\times...\times1!}{n!}$$ is a square number.
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By the same method as
this puzzle
, the answer is
108
.
Tags:
numbers
,
square numbers
,
factorials
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Tags
albgebra
sequences
range
chalkdust crossnumber
partitions
geometric mean
remainders
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coordinates
means
number
lines
expansions
triangles
shapes
dice
menace
square numbers
triangle numbers
averages
neighbours
square roots
2d shapes
percentages
shape
tangents
sum to infinity
cube numbers
spheres
regular shapes
even numbers
crosswords
angles
grids
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products
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gerrymandering
digital clocks
routes
ellipses
perimeter
christmas
crossnumbers
surds
axes
differentiation
speed
rectangles
probability
probabilty
lists
balancing
combinatorics
prime numbers
games
logic
scales
integration
odd numbers
decahedra
chocolate
indices
division
squares
multiplication
pentagons
graphs
money
powers
perfect numbers
consecutive numbers
ave
addition
proportion
determinants
colouring
numbers
coins
time
sets
prime factors
doubling
bases
arrows
polygons
parabolas
clocks
fractions
square grids
planes
sums
functions
tiling
quadratics
digital products
people maths
dodecagons
tournaments
trigonometry
matrices
pascal's triangle
the only crossnumber
irreducible numbers
advent
elections
binary
symmetry
median
multiples
quadrilaterals
wordplay
circles
algebra
multiplaction squares
folding tube maps
geometry
dates
star numbers
cards
factors
unit fractions
hexagons
taxicab geometry
digits
books
floors
dominos
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area
mean
palindromes
rugby
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chess
3d shapes
xor
integers
complex numbers
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