- You have a 3D cube that is only painted on the outside. If you cut the cube into 10 rows and 10 columns on the top, how many cubes will have at least one side painted? - If you see three ants oriented in a triangle, what is the probability they will run into each other assuming they are all going the same speed and they can either go left or right in that same triangle? - How would you estimate the cost of cleaning all of the windows in the city of Belgrade? (these were all questions in the final interview)