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Advent calendar 2015
17 December
All 2015 advent puzzles
~
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In March, I posted the puzzle
One Hundred Factorial
, which asked how many zeros 100! ends with.
What is the smallest number, n, such that n! ends with 50 zeros?
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205
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numbers
,
factorials
,
multiplication
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floors
crosswords
volume
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chess
grids
partitions
number
cube numbers
division
wordplay
christmas
median
multiples
2d shapes
surds
spheres
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integers
numbers
mean
money
colouring
unit fractions
multiplication
parabolas
complex numbers
ave
people maths
graphs
balancing
geometric mean
consecutive numbers
folding tube maps
prime factors
probabilty
planes
products
regular shapes
decahedra
combinatorics
dodecagons
taxicab geometry
matrices
hexagons
albgebra
angles
arrows
irreducible numbers
neighbours
bases
digital products
clocks
triangles
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chalkdust crossnumber
sum to infinity
circles
dominos
percentages
geometry
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indices
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medians
rectangles
binary
doubling
pascal's triangle
routes
dates
determinants
powers
lines
functions
speed
books
integration
dice
sets
square numbers
multiplaction squares
coordinates
factors
differentiation
shapes
shape
polygons
tiling
square roots
fractions
tournaments
sequences
addition
squares
algebra
triangle numbers
perimeter
star numbers
averages
odd numbers
even numbers
square grids
chocolate
time
symmetry
the only crossnumber
elections
axes
xor
3d shapes
cards
expansions
area
means
digits
cubics
range
palindromes
quadratics
lists
sport
probability
logic
games
pentagons
prime numbers
crossnumbers
perfect numbers
factorials
scales
quadrilaterals
coins
tangents
cryptic clues
calculus
menace
geometric means
trigonometry
cryptic crossnumbers
digital clocks
proportion
gerrymandering
consecutive integers
sums
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