This is the repo for https://play.google.com/store/apps/details?id=atorch.statspuzzles.
Nearly all of the puzzles in this app can be solved by hand, with pen and paper. For code that checks some of the answers using simulations (Monte Carlo), see https://github.com/atorch/probability_puzzles_solutions.
Are you looking for the puzzles? They're defined in app/src/main/res/values/strings.xml.
Thank you Roland Illig for translating the app into German, and thank you Roberto Espiño for translating the app into Spanish!
Thank you Mariusz Gromada for publishing mXparser, which is used in SolvePuzzle.java.
Thank you Andrew Gelman for featuring the app on your blog, and thank you to everyone on stackoverflow who helped me figure out how to write an Android app!
I first released this app in July 2014. The app has been rated 6,594 times as of October 2020, and has around 26,000 active users.