This question is from Quantguide(Repeated Flipper): 25 fair coins are lined up and flipped once. Afterwards, remove all of the coins that showed tails, and repeat the aforementioned process until you have no coins left or all of the coins show up heads. Find the probability that you end the game ...

Very distant inspiration from what a family member asked me some years ago on epiphany, this might be a classical logic exercise, but due to the flavor it's quite hard to find the same problem under a different formulation, let alone confirm an original. Additional note: This is a fairly easy on...

So here's the sequence, that I composed on my own. 552175, 228496, 198479, 583317, 136722, 114383, 117045, ?, ?

Take as a semi-related example a series of circles with radii 10, 9, 8, ..., 2, 1. Place the first (largest) circle in the center and subsequent circles around it, keeping tangency between subsequent circles and the central circle. It would look like this: The puzzle prompt is this: Find a seque...