1st interview: --Six horses, labeled 1, 2, 3, 4, 6. They take 1, 2, 3, 4, 6 mins to complete a circle, respectively. If started simultaneously when will they be at the starting position again? --Boxes labeled 1, 2, ... and so on. 1st box has 1 black marble and 1 white marble, 2nd box has 1 black and 2 white, 3rd box has 1 black and 3 white... and so on. If you open a pick a marble randomly, you move to the next box if the marble is white. Calculate the probability that the process would stop at the N'th box. 2st interview: --Why do you want to work here? --What did you achieve in your PhD? --(x+y)^2=4 and (x-y)^2=4, what is x^2+y^2? (I don't remember this exactly. Numbers might be off.) --A small ring rolls on a clock. If there was a pointer on the small ring and the ring starts rolling along the surface of the clock, when will the pointer point in the same direction again? 3st interview (Basic concepts were explained before each question): -- Calculate the fold (it's a seismic term) for a specific geometry of ship sending a signal at a constant velocity after each fixed time interval. -- Draw an auto-correlation of a square wave.
