A 1-Hour OA With Math Puzzles and a Progressive Tax Bracket Coding Problem

Last week I got a call from an IB recruiter asking if I wanted to try out for an SDE role. After I confirmed, I quickly got an OA scheduled — one hour. The OA was split into two parts. Part 1 was middle-school-level math multiple choice. F(x) = 3x - 1, f(f(x)) = 1, what's x? Answer: 5/9 I don't remember this one at all — it should have been a pretty simple question. A square is made up of three e…

Shared by a candidate · reported Apr 2026. Interview formats change; use it as a guide, not a script.