Strict logic is the Basis of mathematics and is also required for the following brain-teasers. You can see in the picture above, three prisms. These have a triangular base area, but are constructed differently.

On the two prisms on the left are listed the Numbers on one corner of it: 5 and 13. You see it as a System? What number must be on the right Prism?

here you can select one of five possible answers, and to know for which Numbers the other readers have decided. If your number is true, you can learn with a click on “solution” below.

1 | 2 to 1. Part: Eckzahl looking for 2. Part of: click Here for the solution