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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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sets
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ave
coins
menace
multiplaction squares
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christmas
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means
volume
gerrymandering
clocks
indices
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geometry
3d shapes
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irreducible numbers
elections
crosswords
rugby
quadratics
spheres
shape
lines
angles
arrows
dice
even numbers
matrices
percentages
polygons
geometric mean
money
folding tube maps
pentagons
decahedra
grids
sums
fractions
factors
palindromes
lists
multiplication
binary
sport
books
integration
rectangles
xor
chocolate
multiples
time
coordinates
bases
axes
people maths
dodecagons
taxicab geometry
polynomials
chalkdust crossnumber
advent
differentiation
perimeter
area
odd numbers
prime factors
logic
dominos
sum to infinity
chess
planes
digital clocks
square roots
cube numbers
consecutive integers
squares
probability
digital products
routes
integers
factorials
cryptic clues
digits
games
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floors
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tiling
pascal's triangle
tangents
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