Challenge #1 – Even Fibonacci numbers

Do you like solving puzzles as much as myself and my Demcon colleagues?
Then I got a challenge for you: can you solve Even Fibonacci numbers? Read the full challenge below.

I wish you good luck.
Pieter Bijleveld – Senior Software Engineer at Demcon


Pieter Bijleveld

Senior Software Engineer at Demcon

The challenge

Each new term in the Fibonacci sequence is generated by adding the previous two terms.
By starting with 1 and 2, the first 10 terms will be:

1, 2, 3, 5, 8, 13, 21, 34, 55, 89, …

By considering the terms in the Fibonacci sequence whose values do not exceed four million,
find the sum of the even-valued terms*.

Write your solution as efficiently as possible in one of the following languages: Python, C++, or C#.

Official submissions are closed, but you can always send your solution to

* This problem is taken from Project Euler.