Interview line splitting What is the sum of the products of endless division? Posted on June 1, 2024 Tags: scaling recursion
The radius of a rectangle What would the world look like if you could only see squares? Posted on May 19, 2024 Tags: scaling geometry
Can you beat the heats? A good old racetrack whodunit. Posted on May 6, 2024 Tags: information-theory trees
Capture the flag How often can you win when you have a number and they have an arrow? Posted on May 1, 2024 Tags: geometry game-theory expectation jane-street
Card collisions What's the chance no card sees its own reflection? Posted on April 21, 2024 Tags: approximation recursion mean-field
Pick a circle, any circle What chance is there, for a circle inside a square? Posted on February 19, 2024 Tags: conditional-probability transformations jane-street
Traffic light chase How long until you meet your menacing assailant? Posted on October 23, 2023 Tags: counting convolution
Pinball lights How many shots does it take to turn the lights on? Posted on October 1, 2023 Tags: master-equation
Unbalanced league How often will geography rob your team of a playoff berth? Posted on September 18, 2023 Tags: diagrams counting inclusion-exclusion