Show me a random puzzle
 Most recent collections 


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


Show me a random puzzle
▼ show ▼

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

© Matthew Scroggs 2019