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 3d shapes, or a random puzzle.


Show me a random puzzle
 Most recent collections 

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

Sunday Afternoon Maths LXV

Cryptic crossnumber #1
Breaking Chocolate
Square and cube endings

List of all puzzles


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


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2019