WAlhazen's problem
WAngle trisection
WBirthday problem
WBlock-stacking problem
WBoundary value problem
WClock angle problem
WDoubling the cube
WEight queens puzzle
WFiring squad synchronization problem
WGuillotine problem
WHadwiger–Nelson problem
WHansen's problem
WHappy ending problem
WIllumination problem
WInvariant subspace problem
WJosephus problem
WKirkman's schoolgirl problem
WKlee's measure problem
WKnight's tour
WMoment problem
WMonty Hall problem
WMountain climbing problem
WMrs. Miniver's problem
WNapkin ring problem
WNecklace splitting problem
WNo-three-in-line problem
WOberwolfach problem
WOrchard-planting problem
WPlateau's problem
WRegiomontanus' angle maximization problem
WSeven Bridges of Königsberg
WSnellius–Pothenot problem
WSquare trisection
WSquaring the circle
WSquaring the square
WThree utilities problem
WTurán's brick factory problem
WWater pouring puzzle
WZnám's problem