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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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,
factorials
,
multiplication
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chalkdust crossnumber
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floors
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proportion
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people maths
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powers
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shape
3d shapes
tiling
folding tube maps
pascal's triangle
angles
star numbers
volume
polygons
taxicab geometry
calculus
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mean
triangle numbers
books
prime factors
sums
chess
indices
coins
bases
cryptic crossnumbers
perfect numbers
even numbers
albgebra
palindromes
probability
grids
axes
sum to infinity
sport
digital clocks
remainders
quadrilaterals
planes
geometry
complex numbers
unit fractions
speed
ave
cube numbers
dates
sets
percentages
christmas
tangents
squares
cryptic clues
integration
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surds
xor
fractions
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factorials
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determinants
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