Colliding parallel people

If two people stand 1km apart and walk in the same direction, how far will the have to walk until they collide due to the curvature of the Earth? (diameter of Earth = 12,742km)

Show answer & extension

If you enjoyed this puzzle, check out Sunday Afternoon Maths III,
puzzles about geometry, or a random puzzle.


Show me a random puzzle
 Most recent collections 

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

List of all puzzles


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


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2020