# Puzzles

## Archive

Show me a random puzzle**Most recent collections**

#### Sunday Afternoon Maths LXVII

Coloured weightsNot Roman numerals

#### Advent calendar 2018

#### Sunday Afternoon Maths LXVI

Cryptic crossnumber #2#### Sunday Afternoon Maths LXV

Cryptic crossnumber #1Breaking Chocolate

Square and cube endings

List of all puzzles

## Tags

probability regular shapes 3d shapes crossnumbers surds books ave polygons functions taxicab geometry trigonometry multiplication mean sums odd numbers time fractions prime numbers complex numbers hexagons proportion pascal's triangle perfect numbers partitions graphs area coordinates division routes geometry cryptic crossnumbers cards doubling percentages wordplay dodecagons digits numbers rugby quadratics symmetry angles factors chess people maths dates averages multiples unit fractions menace clocks differentiation parabolas lines advent palindromes calculus bases number sport coins chocolate crosswords probabilty floors 2d shapes star numbers algebra factorials triangles shapes colouring addition spheres planes folding tube maps scales money integration dice grids arrows integers christmas rectangles ellipses sequences perimeter irreducible numbers speed sum to infinity triangle numbers games remainders shape cube numbers circles means logic volume squares indices balancing chalkdust crossnumber square numbers cryptic clues square roots## Largest odd factors

Source: Puzzle Critic

Pick a number. Call it \(n\). Write down all the numbers from \(n+1\) to \(2n\) (inclusive). For example, if you picked 7, you would write:

$$8,9,10,11,12,13,14$$
Below each number, write down its largest odd factor. Add these factors up. What is the result? Why?

If you enjoyed this puzzle, check out Sunday Afternoon Maths LVII,

puzzles about odd numbers, or a random puzzle.

puzzles about odd numbers, or a random puzzle.