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