Testing For Employment In Nigerian Companies

Going through the job boards on NL I always see, things like ,  bank testing coming up, oil company testing coming up etc.  What type of tests are these? Does anyone have a sample? I am really curious. Obviously you can already guess that I have not worked in Nigeria.

So why all these companies decided to start using tests to shortlist people? If we are talking about applying for certain jobs like computer programming, statistics, engineering etc. We can talk about giving you sample test relating to what you want to do. Maybe give you a programming question to solve if you apply for programing job.

But to me it seems like almost all jobs require some type of aptitude testing. I am not going to bash aptitude testing and the nature of employment testing in Nigeria because i dont know what type of questions are asked.

1. Are the questions related to the work that is needed to be done? eg computer programming = programming questions, accounting job =  accounting questions, public relations job = public relations questions

2. if one fails the test will that automatically mean that one will be disqualified from the position?

3. Do interviewers spend some time before the tests with interviewees? Because some people maybe bad test takers and could be great employees

4. Are there any jobs with major companies that don't require testing?

5. If i have worked in company A for 4 years and I want to go to company B, if they say the position requires testing, will I have to take the test? because if I have to take a test for job in Nigeria right now, I would most likely fail. and my years of IT experience may not be considered valuable

6. Are previous experienced valued? Or are the tests required by new graduates?

I would really appreciate it if someone can post few sample questions. They don't have to be the same questions they have done on tests but I will like to see what the questions look like.

Thanks