mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

Multiples of three

If the digits of a number add up to a multiple of three, then the number is a multiple of three. Therefore if a two digit number, \(AB\) (first digit \(A\), second digit \(B\); not \(A\times B\)), is a multiple of three, then \(A0B\) is also a multiple of three.
If \(AB\div 3=n\), then what is \(A0B\div 3\)?

Show answer & extension

Tags: numbers
If you enjoyed this puzzle, check out Sunday Afternoon Maths XIX,
puzzles about numbers, or a random puzzle.

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

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2026