5 stars: Lots of interesting problems. The topic might better be described as combinatorics instead of probability. Fun way to pass time on the train. Need paper for a few problems though. Some of the images don't show in the hints though, for example, in the hint for the second to last puzzle at the hardest level.
5 stars: The game starts out deceiving simple bit soon gets more difficult (and interesting). I was college professor, teaching statistical analysis and this game was a wonderful experience and review. I would certainly recommend it to even a beginner to the study of probability math as well as high school and college students studying probabilities as well as math majors.
4 stars: A fine range of problems (I'm a quarter into the serious set of puzzles). Some of the hints are above me but I've got onto youtube to find resources to help me understand the coupon collector's problem and the Expected value for the number of tosses to get two heads in a row. I'm learning a lot. Thanks to the author.
4 stars: Applying probability is very non intuitive. The app gives you good practice. The questions are well selected and imply reasonable context. There is a lot of text, but when you're starting to feel drown, there is always a good picture :)
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