Mathematical problem

Hilbert's twentieth problem Hilbert's twenty-second problem Hilbert's twenty-third problem Riemann–Hilbert problems hierarchy problem Invariant subspace problem Problem of Apollonius sums of three cubes assignment problem Klee's measure problem Kuratowski's closure-complement problem Znám's problem Waring's problem No-three-in-line problem map folding Mountain climbing problem Mrs. Miniver's problem napkin ring problem Necklace splitting problem Paper bag problem Parity problem Zero-sum problem Prescribed Ricci curvature problem Prince Rupert's cube angle trisection system of equations solving chess dissection problem dissection problem Tarski's high school algebra problem Tarski's plank problem Sleeping Beauty problem Thomson problem Basel problem Behrens–Fisher problem bin packing problem Hilbert's thirteenth problem Burnside's problem Fagnano's problem Tarski's circle-squaring problem Kirkman's schoolgirl problem Kepler conjecture Hilbert's tenth problem