How many questions have been solved up till now?

A twenty-two-year-old student here may have solved one of the great enigmas of mathematics. Elin Oxenhielm of Stockholm University’s solution of part of Hilbert’s sixteenth problem will be published next week. In 1900, German mathematician David Hilbert presented a set of 23 unsolved problems to a congress in Paris. Three remain unsolved today: numbers six, eight, and sixteen. The sixteenth problem calls for the creation of a topology of real algebraic curves and surfaces. The solution for the second part of the problem is being published in the journal, Nonlinear Analysis.