Go to main content

"A prisoner is trapped in a cell with three doors. Behind one of the doors is a beautiful palace, behind the second door is a fire-breathing dragon, and behind the third door is a room with a pile of gold. However, the doors are labeled with Fibonacci numbers (1, 1, 2, 3, 5, 8, ...). The prisoner can only open a door if the Fibonacci number on it matches the sum of the Fibonacci numbers on the two preceding doors. Which door should the prisoner open first to escape the prison?"

It sounds like a boring arithmetic exercise. But look closer. This sequence dictates the spiral of a hurricane, the arrangement of leaves on a stem, the breeding pattern of rabbits, and the curve of a nautilus shell. It is the blueprint of growth.

Before we break out, we have to understand the lock. The Fibonacci sequence is deceptively simple. Starting with 0 and 1, each subsequent number is the sum of the two preceding ones: