Question 83
A path in the plane leads from the point $(0,0)$ to the point $(6,6)$, where in each step one can go either $1$ to the right or $1$ up. How many paths are there that contain neither the point $(2,2)$ nor the point $(4,4)$?
Math Olympiad Vault · MathNet 2008-part-04 — 165 problems (EN–VI)