We’re throwing it back to our JEE Advanced prep days - combinatorics, counting, and all that good stuff.
This week, @research-focus-group will explore how to distribute balls into boxes and how the number of possible arrangements changes depending on whether the balls or boxes are distinct or identical.
It’s a deceptively simple concept that shows up surprisingly often in interviews (even if not directly in day-to-day quant research jobs). Understanding it deeply builds intuition for counting arguments, symmetry, and probabilistic reasoning.
Start here: Balls and Boxes - Topic Link
Follow ups:
- Ask yourself if you’re able to intuitively understand the identical balls and boxes case
- Can you write the solutions using 1 dimensional DP? i.e. not using space in the order of M*N