Brain cells

What this combinatorial logic interview question tests

This is a medium-difficulty puzzle that probes your ability to set up and solve a system of constraints. It requires you to translate a description of cell connections across two hemispheres into algebraic equations, then solve for an unknown quantity.

The core skill is recognizing that the total number of each type of cross-hemisphere connection is determined by the product of cell counts in each hemisphere, then working backwards from known connection counts to deduce the original cell populations. Interviewers use problems like this to assess clarity of reasoning under time pressure and comfort with constraint-based problem solving.

• System of equations from combinatorial constraints
• Mapping problem description to mathematical variables
• Systematic enumeration and logical deduction