What's the process Google follow to select candidates for Google
Answers? I have applied for that 2 days ago and I haven't recieved any
answer. How many people apply everyday? I think it's not to much
difficult to select candidates for this, it only takes 30 seconds to
review every request.

Thank you for your question.  We get a lot of questions like this one
and are choosing to answer this question now for that reason.

The number of applicants to be a researcher for Google Answers is
privately held information.  However, as you can read on our web site,
we put applicants through a rigorous two-stage process of application,
and they are required to adhere to high standards during the
application process as well as once they are researchers.

Please rest assured that we are processing applicants as quickly as
possible.  You will likely hear from us within a few days if not
sooner.

If you have further questions about the status of your application,
please email us at answers-applications@google.com.

Thank you for your interest in Google Answers.

I will send an e-mail to answers-applications@google.com to know the
status of my application. Thank you very much for your answer.