Since its a Trainer job, you will be tested upon things that you are going to teach.
for eg. If you knew Java and interested in teaching Java, you will be given a test in their PC. (Test created by already working trainers or peons.) Say, a multiple choice questions in their website.
The website Exam will contain too many errors. You will tolerate them to complete the exam. If you get poor results, you can't blame them. They will decide your salary from the exam results. Even if you are an industrial master and coming to share your knowledge with students, you will be treated like you knew less than they required.