Sofya Aleksandrovna Yanovskaya, a Russian mathematician of Jewish origin of the 20th century specialist in logic, posed different problems to her students so that they would solve them with perseverance and so that they would continually ask themselves: what am I doing? where am I going?  

We propose you to solve the following mathematical logic problem.

Look at this list of numbers: 1 1 3 4 4 4 5 5 5 6. You have to place them in the circles of the drawing, keeping in mind that the number that is written in each triangle is the product of the three that are in the vertices. Where does each number go?