Very nice probability puzzle…though involves basic knowledge of probability and algebra. Found this again on http://www.midcipher.com.
Consider a lab rat in a maze. There are four paths that can be taken with equal probability. Path A leads to exit in 5 minutes. Path B leads back to start and takes 8 minutes. Path C leads to exit in 3 minutes and last path D is 2 minutes long and leads back to start. What is the expected escape time of this poor rat from the maze?
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