Arrange ten coins in a bowling formation. Fewest pennies to remove so no three pennies that remain have centers that form an equilateral triangle?9yr ⋅ marconius-14080 ⋅ se/puzzling
Arrange numbers to the equations, so if we turn the equations upside down, they are still right7yr ⋅ jamal-senjaya-28756 ⋅ se/puzzling
Numbers on a dartboard - we know why they are in that order but how was it calculated without computers?9yr ⋅ chasly-from-uk-14177 ⋅ se/puzzling
Smallest number of matchsticks for a 3D structure with 6 matchsticks at each vertex9yr ⋅ fibonatic-8810 ⋅ se/puzzling
Network connection: Create a network that guides the signal from start to goal9yr ⋅ bmyguest-5840 ⋅ se/puzzling
I have a puzzle that is colored dots in rows and columns and I need a place to start7yr ⋅ holliepologie-40303 ⋅ se/puzzling
What is the pattern in this IQ test puzzle with spotted triangles and arrowed circles?10yr ⋅ klm123-28 ⋅ se/puzzling
The kids moved when we were gone! What is the likelihood that white is winning?8yr ⋅ greg-hastings-24935 ⋅ se/puzzling
What is the largest, compact connected-network polyomino for these tiles?9yr ⋅ bmyguest-5840 ⋅ se/puzzling
What is the minimum number of matchsticks that you can use to build expressions having the following results?9yr ⋅ cool-guy-7482 ⋅ se/puzzling
What to do when the official Rubik's cube solving sequence breaks?10yr ⋅ warspyking-2383 ⋅ se/puzzling
Are there 'Hexanum' puzzles that require advanced methods to solve?10yr ⋅ disgruntledgoat-125 ⋅ se/puzzling