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