Google Entices Job Searchers...

Mysterious banners at a Cambridge, Mass., subway stop have commuters scratching their heads. The signs, challenging passers-by to solve a complicated math problem, are actually a cryptic pitch by Google, which is looking to hire more brainy engineers.

The message at Harvard Square also appears on a billboard in California's Silicon Valley, but Google's name is nowhere to be found on the ads. It simply states:

{first 10-digit prime found in consecutive digits of e}.com

In case you're wondering -- or forgot -- e is the base of the natural system of logarithms, having a numerical value of about 2.71828 (though the number goes on forever).

The correct answer to the banner problem leads to a Web site that poses yet another puzzle. Eventually, the determined problem-solver lands at a Google Web page that asks the smart, or lucky, few for a resume.