mscroggs
.co.uk
mscroggs
.co.uk
blog
puzzles
academic
talks
contact
subscribe
↓ ☰ ↓
subscribe
Loading image...
Advent calendar 2025
24 December
All 2025 advent puzzles
~
More information
3 and 5 are both factors of 2025, and 3 and 5 are the only two prime numbers that are factors of 2025.
What is the largest three-digit number that has both 3 and 5 as factors and no other prime numbers as factors?
Show answer
Hide answer
The other three digit numbers that have 3 and 5 as factors and no other prime factors are:
3
1
×5
3
= 375
3
2
×5
2
= 225
3
3
×5
1
= 135
3
3
×5
2
=
675
3
4
×5
1
= 405
Tags:
numbers
,
factors
,
prime factors
Archive
Show me a random puzzle
Most recent collections
Advent calendar 2025
Advent calendar 2024
Advent calendar 2023
Advent calendar 2022
List of all puzzles
Tags
axes
ave
neighbours
remainders
mean
fractions
people maths
combinatorics
factorials
trigonometry
grids
quadratics
books
binary
numbers
factors
shapes
chalkdust crossnumber
folding tube maps
shape
3d shapes
medians
tiling
proportion
parabolas
sum to infinity
sums
clocks
digital clocks
matrices
coordinates
chess
products
lines
geometric means
dates
decahedra
irreducible numbers
speed
complex numbers
digital products
advent
percentages
division
2d shapes
indices
doubling
palindromes
averages
star numbers
arrows
menace
range
sets
area
probabilty
tournaments
perimeter
triangle numbers
angles
quadrilaterals
algebra
bases
consecutive numbers
christmas
multiples
geometric mean
probability
colouring
square roots
dominos
geometry
wordplay
multiplication
expansions
median
square grids
cryptic crossnumbers
integers
hexagons
taxicab geometry
gerrymandering
unit fractions
crossnumbers
prime numbers
regular shapes
floors
sequences
time
spheres
integration
sport
surds
volume
prime factors
balancing
dodecagons
lists
pentagons
squares
polygons
square numbers
dice
ellipses
chocolate
xor
powers
polynomials
pascal's triangle
cryptic clues
calculus
rectangles
triangles
digits
crosswords
means
elections
games
addition
circles
cubics
even numbers
money
number
symmetry
multiplaction squares
planes
coins
cards
functions
cube numbers
scales
routes
consecutive integers
albgebra
graphs
determinants
perfect numbers
partitions
differentiation
tangents
logic
rugby
odd numbers
the only crossnumber
Archive
Show me a random puzzle
▼ show ▼
▲ hide ▲
Most recent collections
Advent calendar 2025
Advent calendar 2024
Advent calendar 2023
Advent calendar 2022
List of all puzzles
Tags
shapes
polynomials
powers
time
geometric means
fractions
xor
averages
unit fractions
coins
geometry
even numbers
sport
grids
remainders
advent
dodecagons
geometric mean
planes
calculus
crossnumbers
area
combinatorics
quadrilaterals
volume
dominos
the only crossnumber
perimeter
digits
indices
coordinates
algebra
elections
trigonometry
square grids
numbers
addition
money
tangents
prime numbers
parabolas
symmetry
prime factors
cube numbers
ellipses
hexagons
neighbours
sums
probabilty
tiling
integers
factors
crosswords
matrices
digital products
median
rugby
bases
dice
christmas
polygons
speed
surds
rectangles
consecutive integers
floors
determinants
dates
consecutive numbers
menace
lists
palindromes
circles
multiplaction squares
square numbers
pascal's triangle
cubics
chalkdust crossnumber
graphs
cards
wordplay
range
proportion
integration
clocks
means
multiples
people maths
cryptic clues
sequences
star numbers
medians
sum to infinity
arrows
partitions
number
square roots
pentagons
albgebra
quadratics
chess
ave
lines
odd numbers
mean
logic
colouring
perfect numbers
taxicab geometry
triangles
balancing
chocolate
gerrymandering
angles
sets
digital clocks
multiplication
expansions
irreducible numbers
percentages
axes
cryptic crossnumbers
complex numbers
scales
routes
functions
triangle numbers
decahedra
spheres
regular shapes
probability
squares
differentiation
division
shape
folding tube maps
factorials
doubling
books
products
binary
2d shapes
tournaments
3d shapes
games
© Matthew Scroggs 2012–2026