Brainteasers

Mental math, logic puzzles, and the curveballs that test how you think on your feet.

1. 1

   Brainteasers and market sizing

   Brainteasers are a small slice of IB interviews, usually filler. The one that actually shows up is market sizing, and it's graded on your structure and stated assumptions, not the exact number.

   7 min read

   ›
2. 2

   Mental math for the interview

   No calculator in the room, so build reflexes. The rule of 72, quick percentages, growth math, and estimating IRR from MOIC, all with clean round numbers.

   6 min read

   ›