Can you solve this?

To quote the Hiring Ad campaign:

we unveiled a billboard that's a bit unusual in that it promotes Google only to one very narrow constituency: engineers who are geeky enough to be annoyed at the very existence of a math problem they haven't solved, and smart enough to rectify the situation.

If you're up to the challenge and are diligent enough, break your head trying to solve this. I know what I'm going to be doing this coming weekend...