What is the right method to tackle such exams so that maximum questions are answered?

The right method is that one should be extremely focused during the exam. We should not waste even slightest of time. Once the Test begins, do not waste your time in reading the entire paper rather you should start in a planned manner. You should have already decided in which order you are going to solve the paper. Since these questions are of objective type, read a particular question and immediately mark your answer on the answer sheet. In case you find a particular question difficult, skip the question and go on to the next question. The question so skipped may be solved at the end, if time is available.