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Probability Riddle Using Python: The Roads We Take


The figure below is a map of part of a city: the small rectangles are blocks and the spaces in between are streets. Each morning a student walks from intersection A to intersection B, always walking along the streets shown, always going east or south. For variety, at each intersection where he has a choice, he chooses with probability  1/2 (independent of all other choices) whether to go east or south. 

Find the probability that, on any given morning, he walks through intersection C

Python Solution:

Riddle Source: